The best way to polish the Metal IMO is with a Brass Tumbler. It is what guys who reload ammo use to clean their casings.

I don't know about putting Ajax in a dishwasher but the plastic bits should be ok. I just use Novus 1 and Q-tips.

I measure the posts with a ruler then search for the best match by picture on Pinballlife or Marcospecialties.

I've put plastic posts in the silverware holder of a dishwasher - seems to get you a nice head start - then hit them with a toothbrush and some novus - its alot of tedious work those star posts, Im sure there are other better ideas out there.

just dont do a heat dry on the dishwasher

you can download your manual on IPDB.org and in there should have your part numbers

If they are star posts I would just replace them if they look worn/shabby, or you could soak them in warm soapy water and clean muck out of the edges with a tooth brush. If the plastic posts are straight, I'd use novus 2 and 1, rags and cue tips, or just replace them.
When I clean metal parts I use Autosol metal polish and rags, gets rid of most crud, long hard job and sore fingers ahead, some metal parts like nuts and posts I like to put them in a cordless drill and spin them in a rag with polish on, they clean up real quick.

Bugray I do something similar - I put alot in my vice and use a light wire wheel on them
come up super shiny and steel wool - also bought a big bag of everything from pinball life - has nice new shiny nuts and bolts

I use the brass brush on a Dremel Tool to clean rust and corrosion off of screw heads and other metal parts that won't fit in the tumbler. The Brass brush won't damage the metal surface. Also use NevRdul afterward.

My worst hate of cleaning metal parts has to be wire form ramps, they take forever, it's painstakingly boring, but the results are great, shiney new looking ramps.

whatever you do dont soak white plastic posts in bleach they come out yellowish

SOME parts manuals actually have the part numbers for the posts, but only some. For instance, my buddy has a Bride of Pinbot, which as every little nut, bolt, screw, washer, post, rubber, etc... listed one way or another. My Black Knight, absolutely nothing. Though there were also factory parts list manuals, which I've never had the opportunity to look through.

Here's an odd question... anybody tried polishing the plastics in a vibratory polisher yet? Eastwood sells a bunch of different polishing media, some of which say to use with plastics. I might try a few sacrificial busted parts to see what happens with walnut.

-Hans

I would use corn cob with plastics. I believe walnut is too harsh.

I put everything in the dishwasher. Works like a charm, especially on ramps! Just don't put it too hot, and always test drive first with one obscure plastic just to make sure your dishwasher doesn't have any destructive powers!

The dishwasher is not the last stop though. It gives you a head start. After that you will always need some manual labour. There is no "easy way" for plastics I believe.

For metal parts I like to use a product called "brillo". It's like a little sponge made from iron wool and it has some kind of soap in it. It is normally ment for cleaning your pots & pans, but works great on metal rails and those chrome ball guides!

For starposts A toothbrush with some novus works wonders. I have an old electrical toothbrush that I use.

A tumbler will be my next investment, I think that will be great for posts, screws, balls and other small parts...

Some parts work with multiple manufacturers so it may have multiple part numbers. Also, aftermarket parts will reference which part they replace.
The older manuals are crap when it comes to parts numbers. Even the Operator's manual didn't list all the parts numbers. For some parts, you have to do a bit of research. I look for parts on several of the suppliers to try and verify with their pictures and descriptions and then cross reference the part number one will give on other sites. Usually, they will say something to the effect "For early Bally/Sterns" or give a year range like "For 1980-1991 Williams"