[hypoxia]

Cleaning contacts on a micro switch is for the most part futile.  There's just no way to get contact cleaner onto the contacts.  You definitely do not want silicone on the contacts.  They are cheap and readily available at Newark, DigiKey, Mouser etc..  FWIW,  on many airplane radio transmit buttons there are two microswitches stacked on each other, wired in parallel to insure radio communications when one micro switch fails.  When they fail it is commonly intermittent and difficult to pinpoint.  When it happens I automatically buy two and replace both, you'll go crazy trying to troubleshoot.

I would get 2 microswitches, drill the old ones out and use a small screw to reassemble, you shouldn't need rivets.  Amperage and the arm length are about all you have to consider.

Micro Switch