The spring for the Release Rail on the Beomaster 8000 seems to be one of those parts that goes missing. I stumbled upon a source for a replacement spring by accident the other day. The cool thing is that the source is close to home wherever you live.
There is a spring similar to the release rail spring holding on the button board.
This spring could be replaced with a washer if you need to repurpose it.
For reference, here is a picture of a original release rail spring along side a button board spring.
I don’t know how many times I’ve looked at the back of the button board and not noticed the spring.
Hope this helps someone,
Glitch