Depends on current overall condition and what you paid for it if you don't want to put more into it then what it may be worth when your done,
I have Bally EM parts for it and Manuals, schematics, trouble shooting tips, Etc.
But just a suggestion, you could probably get more assistance on NLG, NEW LIFE GAMES forum for your Bally as they lean towards the later electronic slots,
https://newlifegames.com/nlg/index.phpas most the folks on here are Vintage/Antique Slot Machine collectors, repair and parts people!
I just happen to burn the candle at both ends after working in the casinos in the 60's/70's and catching both the older mechanicals as well as the Bally's in the casino slot shop that came out in 63/64 time period and Service and have parts for both!
If you do work on it and need parts, reach out to me!
Ciao!
MONTI