SOL-20 keyboard question

[J.C. Wren]

    The SOL-20 has powered up, but the keyboard is sorta FUBARed.  The 
LEDs work, but none of the keys do.  I pulled the keyboard, and shorted 
a couple row & column drivers, and the keystrobe strobed.  I ended up 
removing the PCB from the key assembly, and determined that pads inside 
the keys are shot to hell.

    They look like they should be mylar coated or silvered Kapton discs 
with a foam backing.  The foam is mostly decayed, and there's virtually 
no silvering left on any of the discs.  They few that do have only the 
slightest fragments.  I assume this is supposed to be conductive, 
because pressing a disc against the PCB pads doesn't trigger a key, 
while touching the PCB with my finger does.

    Can these be rebuilt, or are replacement switches available?

    --jc