Well it's to bad you won't be able to keep it out of the weather.
I've got the same setup you have on the back of my 52 6100 and it's still in good shape, but judging from what the whole thing looks like I don't think it spent it's life outside.
Right now it is outside but the bed is covered with roofing rubber which I managed to get cheap at an auction.
I've tried Thompson's on wood and like Dave said, put it on every year, but who feels like doing that.
Take a lesson from that oak you see laying in the woods, because moisture is the enemy. If the oak stays dry it will last but the oak that stays wet a lot, will rot.
My bed was made with tongue and groove oak and it's the between the boards that rarely drys out and begins the rot.
I think I'd try the motor oil trick, if I couldn't do any thing to keep it dry.
Dan
