You’ve done well so far.
When you hear coils lock on, immediately turn the machine off. It takes only a few seconds for them to melt and cause big problems. Coils also are relatively pricey to replace, and if properly cared for you will almost NEVER need to replace them.

The score reels are guaranteed to be gunked up now. It happens. They’re almost 50 years old and they’ve been abused most their life. There should be several guides around here for rebuilding Williams score reels.
Forgive me for not digging as it’s 3am here.

I’m not sure which is the “pop” you speak of. Probably a chime coil? Maybe the knocker?
https://www.ipdb.org/glossary.php

This is a great resource. Peruse through the glossary. Familiarize yourself with the terminology and we will be better able to help you. If you work on classic cars than you’re in good shape. EMs are very simple once you understand the theory of operation. No circuit boards to blow up. Just relays and point to point wiring.
90% of your problems will be dirty/oxidizes switch contacts.
EMs need to be played every day. The switch blades are self cleaning when properly adjusted, so the more you play it, it’s very reasonable that it will start working better and better.

The other 9% of your issues will consist of misaligned/broken contacts
filthy coils with worn coil sleeves
Gummed up stepper units (from old oil and grease that lazy people tried to use as a band-aid)
Hint: DO NOT “LUBRICATE” ANYTHING ANYWHERE AT ANYTIME ON A PINBALL MACHINE.
It’s all dry lubrication with nylon and metal on metal.

There is an exception that the wiper/spider blades actually do use a SMALL amount of dielectric grease.
Some collectors swear by Super Lube synthetic. Others will have a heart attack if you don’t use the old school natural stuff that Steve at PBR (Pinball Resource) sells. Your choice really.

Stuff you should do for maximum performance:
Rebuild the flippers mechs with new plungers and links (they’re worn out and operators almost never replaced them!)
Rebuild the slingshots, same thing
Rebuild the pop bumpers
Don’t skip the leg levelers. They’re so cheap and the old rusty ones on that machine are most likely worn through. New ones are awesome and you can nudge even better!

Don’t use a harsh file to clean contacts. It’s a bad idea. Use a flexstone file, business cards, 1000 grit sandpaper. Something gentle. They’re mostly gold plated so you don’t wanna ruin them.

That’s everything I can think of while nearly passing out tonight. Good luck! We’ll be here for you if you’re willing to learn. Don’t jump in too fast before doing your research, there’s a lot of things that seem obvious but once you learn more about these machines you realize it was counterproductive!

^^ this ^^…and the schematic diagram is your friend. Learn to read it. It will aid you in diagnosing problems.

Also, the locked on coils likely indicate a switch that is closed when it should be open and/or a short. FWIW none of my em games have never really made more than an initial click when turned on. A freshly powered up em should typically be in its game over state.

you may find these helpful. annnd PM - checklist sent Enjoy your new obsession, you are in the right place!

https://pinside.com/pinball/forum/topic/em-pinball-circuits-basics-to-not-so-basic

http://www.pinrepair.com/em/index.htm

https://pinside.com/pinball/forum/topic/how-to-efficiently-ask-for-pinball-repair-help-em

Pinwiki has great articles about your first pinball machine, common issues for each generation of pin to address, and lots of repair tips.

Read the articles Pinball for Beginners and General for all games. Then read up on your generation of pin.
https://www.pinwiki.com/wiki/index.php?title=Main_Page

I have the same machine. It was my first pinball machine and I knew nothing about them. I just needed a project during the first phase of Covid-19. Mine would only turn on all the lights when I first got it. I started at the beginning, trying to figure out why it wouldn't eject a ball to the shooter. Once that was resolved, I just addressed each issue as they became noticeable. When you really get into it, make sure that tic-tac-toe grid in the middle of your playfield is working properly. Each time you score 100 points, the grid should advance to the next number. When you score 500 points, it will advance five numbers. I played mine for six months or so not knowing this. It would only advance when I hit the target at the top of the grid. Once I got the grid to advance properly, it was a completely different game. There's a thread on this, too. It is as simple as adjusting one switch on the 100 point relay located in the back box.

In looking at your photo, I see that you might be missing a nylon nub on the plunger for your middle chime bar. It looks like the chime bar has been rotated due to a hole in it. Here is a thread to the discussion when I had the same issue: https://pinside.com/pinball/forum/topic/williams-chime-bar-failure#post-6125383. You can keep using the chime bar with the hole in it, buy a new one or make a new one. You should replace the plunger, though (or add a nylon tip to yours).

You will have just as much fun fixing/restoring your Gulfstream as playing it. Pinside is such a great forum so you are in the right place. I've always gotten quick replies and suggestions without the snarky comments like on other forums. Make sure your wife is ready to see "Marco Specialties" on your credit card statement and "The Pinball Resource" in your checkbook registry. Both are very reliable suppliers and it is worth every cent to keep them in business.

Have fun.

And since you said that you have worked on other vintage restores, let this be said:

For the love of all that is holy, contact cleaner and WD40 should not be used anywhere near a pinball machine.

All though focusing on mainly Gottlieb pins, go to this site: pinrepair.com/em and read from top to bottom. There is Williams stuff here as well but a lot of this information is for general EM repair.
This is a quote from the website creator Clay:

"The key is your power of observation, which is definitely your strongest asset when fixing EM games. Where solid state games have "little black boxes" (chips), and you need to know what the input and output to these black boxes may be, EM games don't have any black boxes. Nearly everything can be seen. Hence for many people, it's far easier to fix an EM game, as long as you know what you're looking at!"

First machine and it’s set up in the dining room. Like this guy already.

Yep. I would already plan on moving Thanksgiving dinner to another room.

Nah. Just lay a piece of cardboard on the machine, and put the casserole dishes on it!

Welcome to the addiction! Your back ground is common to many of us.
My suggestion with a new game is look it over carefully before ever plugging
it in. Look for loose bits floating around in the cabinet as they will give you
your first hints on what is bad. Broken off relay/switch contacts and loose
screws are often a hint but not always. Look for broken, fried and loose
wires and solenoids. Finally, with power off, move the armature of each relay
and switch to see if its sticking, broken or misaligned. This is a good time to
clean them too. NEVER use abrasives on most contacts as they are plated.
Use old non-glossy business cards dipped in alcohol. Others use other juice.
NOTHING is oiled or greased except for gearboxes.

Read everything you can get your hands on about how EM's work. Its
overwhelming at first but once you get a feeling for what all of the bits
do it'll all fall into place.

Most of all be patient and don't take chances. AND if you don't know how
to read a schematic. learn.

The very first thing an EM does when you start a game is go through the
reset sequence. You're not there yet but thats often where it gets complicated
and frustrating.

And yeah, this is a wildly addictive but fun hobby with a bunch of great
guys & gals. I started 34 years ago, the house & garage is full. And
I'm still looking!

Have fun!
Steve

Nice work so far!

Not bad at all!
You worried me with the “lubricated the metal on metal parts”
Please clarify what you mean??? The ONLY parts that should receive lube of any sort is the steppers (finger/spider contacts) I believe the score motor may be lubricated as well but I’ve never bothered.

Everything else uses no lubrication at all. They use nylon sleeves in the coils

Nice job on the paint, it is very well done compared to most the newbie jobs we see!!
Very well done on the head, looks great!

Aluminum

My recollection is that the playfield protectors for under the pop bumpers aren't stuck down.

Gottlieb used an acetate shield, no glue. It kinda sucks as dirt does get under it. Better than nothing but I use Mylar instead. Would assume most others do too.

I use the acetate shields, to install them you need to desolder the pop bumper light socket so you can remove the whole assembly

Alberto

I think I'm correct in saying that Gottlieb machines used the acetate type platters. Nothing wrong with them ( I tend to use these all the time when overhauling pop bumpers) but, it's important to keep your playfield clean or dirt and grit will get underneath and soon wreck the artwork underneath. And they need to be carefully cleaned underneath too because it's very easy to bend them during cleaning and spoil the pop bumpers performance as the ball is being impeded. So hence why many people prefer the adhesive ones. Horses for courses really.