I recently purchased a Racal-Dana 1992 Counter off eBay for a bit more than I wanted to spend, and figured when I got it, it would be non-functional. But, when it arrived, it was fully functional, albeit with the same mushy buttons that everyone complains about with these older units. Turns out Racal-Dana used a molded rubber for the “spring” of the button, which over time decomposed/cracked and left the user with buttons that didn’t really spring.
The common fix is to use more modern buttons and solder those in, then modify the keys to fit on round button actuators vs the cross-top ones that are stock. I’ll post a new article about that fix once I buy the buttons (waiting for other stuff to order from Digi-key/Mouser).