Vintage Synth Repair

I've been offered to buy an OBXa in a mint cosmetic shape but I've been 
told that it has one missing voice board

What are the chances to make it play ? can I "fool" the system by using 
some kind of jumper or short to make it "think" it only has one less 
voice that what it should have ?

Or that the OBXa can work with just any number of voice cards you'd put 
in it ? In other word, can I just take out or install as many cards as 
I wish and it will still power up and play ? Are those card installed 
one on the top of the other (modular build) ? 


Any help will be much appreciated !!