HI Donald,
Nick is giving (as always) very sound advice there.
Working on a dirty or fluff-covered chassis is not the most encouraging scenario, and also whilst cleaning off the grime, you may spot other things that need attention that would have otherwise perhaps been missed.
I used a smidge of trombone oil (a very thin oil) on the push-button assembly -
not on the contacts though, to remove some traces of rust on the mechanism. Its a thin, 'creeping' oil, and gives a thin film over the area to which it is applied. Servisol 10 is my choice of contact cleaner/lubricant, but everyone has their particular favourite. Tony.
