I'm with you on the Olys, mine are usually covered with frog spit and bird poop, but they just keep on shooting.
Somewhere in my basement, I've got an OM-2n, and I'm not really sure how many times I used it for shooting football and lacrosse games in driving rain and snow. It just kept on going and going...
I haven't even seen the camera in ... wow, it must be at least 13 years... Since I moved into my house.
Mark