I have done a lot of SS ballys and for around $400 you can get all the Altek boards.
MPU, Selinoid and Lamp Driver. They have a 3 board special deal.
If you have a sound card then you have to find it on ebay.
Typically the lamp driver is ok.
The MPU rots due to battery leakage and the Selinoid Caps go bad on that board.