Forgot to mention - I have a EBD in my collection that is unrestored (and never for sale) - so if you need a reference game for photos etc - The machine is at your disposal 

I am hoping that there is some logic to a Bally game
As you know, I have a couple
From those I should be able to work out how a Bally game is built
I was needing to know if there was any part that was only used on EBD