Sounds like you have one of my Dad's old Bingos. Where are you located ?
Unfortunately, I am not very good as these machines. I have restored a Miami Beach with Dad, but I did the cosmetic stuff. Dad and my Uncle used to fix these in their sleep. I do have a Cypress Gardens, pulled out of hibernation (hidden since 1991) - here is the thread -
http://aussiepinball.com/index.php?topic=12180.0In terms of Backglasses - I might have a spare, or Daniel has one as mentioned.
There is a guy on Youtube that has some excellent guides - well worth the $
You have a unique project on your hands. document it here and you might have some assistance as you progress.