Two questions for the OP: do you enjoy the hobby and do you need more
stress in your life? If the answers are yes and no, don't get involved with
putting pins on location.

I did this with a friend many years ago now. Just for fun and to get a feel
for what it was like. Just like you, enjoy fixing up pins. We did this for about
7 years, made a decent amount of money at it considering we put out older
machines.

But here's the rub; when your machines get broken into, scratched up,
generally ruined in the long haul AND you have to make trips out
frequently to deal with this type of damage, as well as the usual maintenance
it'll get old fairly fast. In other words it'll no longer be fun.
Actually kept me from enjoying the hobby aspect for a while.

IMO trying to make money from a hobby is stupid!

Insurance is also very important these days. All it takes is one
dumb-ass teen that tips YOUR machine over onto himself
or someone else and YOU get sued. This almost happened to
me and the reason I bailed out. The risk is too great.

And a follow up, after I bailed the location owner decided to
contact a real coin-op outfit, who put their games in and
were all STOLEN within an year.

My sage (OK, free) advice is buy project pins, fix them up and
sell. Use the profit to buy more. Repeat. Thats what I've been
doing and having a blast.