Not sure if this matches the same form factor, but check out the KSC401J 50SH item -- the data sheet (page 1) shows 5,000,000 cycle operating life:
http://www.ck-components.com/14422/ksc_31aug10.pdf/
I'd like to get my hands on your old BROKEN switches then order some of these to see if they will fit, so if/when you (or anybody else) gets replacements from TM -- or if you have any old, broken ones on-hand -- drop me a PM.
The small PCB looks VERY small, so it might be possible to replicate the boards, procure the 5,000,000 cycle switches, locate the proper connector for the cable, then produce a "long-life" replacement switch kit for a fairly reasonable price.