[Heathkit] SB200 Wafer Switches

[Bruce Hudler WK3A]

Hello All,
Me too - looking for replacement ceramic wafer switches. 
I have (2) SB200's that need these.
#1 has blown rear section, possible to replace only the fingers.
#2 has blown front section - not repairable as the rotor and finger vaporized. 
Harbach shows replacement rear section for $40 but not in stock.
 No idea who has the front section. 
Is there something used to dissolve the tarnish on the contacts? I don't want to use anything abrasive obviously and contact cleaner won't cut it. I've used a good pencil eraser before on rotors but that doesn't get into the fingers. 
Thanks!

Bruce WK3A