A late date to be adding to this awesome list of checks, but I do have one more, which I learned from a collector just yesterday.
"Push off" is a check to do (empty revolver, check twice!), with barrel pointed in a safe direction. Cock the hammer all the way back. Push firmly (don't try to bend it!) forward on the hammer. If it falls, there is excessive wear on the trigger, hammer, etc. If it holds fast, then it passed the "push off" test.