Sometimes you just gotta pay the 15 bucks rather than try to cobble together a repair on a 30-year old part that's never going to be reliable. I'd just get a new switch, as that doesn't seem to be a reasonably repairable part to me. It's about 20 years past its service life.
Surely you can think of some other parts to buy to lessen the sting of that $10 shipping as well.