Have you given any thought to changing over to leaf switch buttons (and joys for that matter). If it's the clicking from the microswitches that bothers you, that'll do it.
Ponyboy has some leaf switches that will fit in place of a microswitch on a horizontal pushbutton.
If it is actually the spring, swap it out with another (just in case, by some remote chance, you've never done this/don't know how -----> remove microswitch, squeeze 'feet' of button plunger together and push through to top of button., remove and replace spring), or just swap out the whole button.
If it's a button used often, just swap it with a button you use less frequently i.e. admin button or pause or coin up or whateva.