Electrical Contact Cleaner Spray 5oz Aerosol Deoxit Metal Connector Cleaning
D- Series D5
This is a product I have used with success. I have also Un-crimped the zinc potmetal bodied hard case switches from 67/68 cars & kickdown with limited success. Disassembled, removed crusted grease and burnished (Polished sliding contacts) using craytex rubber abrasive stick (Heck a pencil eraser works also.)
Then just used an OHM meter to check continuity across terminals when closed & opened.
JIM
JIM