Years ago, before dirt was invented, I was able to buy a frame then add any of the dozens (Hundreds?) of wafer deck/switch combinations. Centralab and others made these available.
To the best of my knowledge, you just can't find this stuff anymore to "roll your own" switch at the parts houses.
Although, Mark Oppat might possibly have the parts. He can really surprise you with what he can supply.
Normally, unless its a special high current switch or a weird switching conbination, I have been able to salvage a wafer deck from another switch and replace the defective one. ( I have saved a couple of boxs of old frames and wafers and just hunt thru it until I (Hopefully) find another wafer deck that is the configuration I need.)
As another esteemed member pointed out, one can just remove the bad contact section and replace just the contacts, and using a tiny screw & nut, re-attach the contacts to the switch wafer deck.
I have done this with good success in the past.
In reality, the hardest part of that is finding a screw & nut small enough to fit through the old rivit hole.