My 50 was in storage for over 20 years and the mice had found their into the headliner and I believe it was through the pillars - I think that is the right term for the columns at either end of the windshield which support the roof. In any case, when I started working on it again a new headliner was required but before I put it in, made some "barriers" from aluminum window screen and stuffed them into the pillars from the top. Now some years later, I find that the rodents had made their way past these and ruined the replacement headliner as well as making the truck really stink. This time, I made cones out 1/4" hardware cloth that were maybe 6-7" long and stuffed them into the pillars. But, I don't know if they are really blocking rodent access to the penthouse suite or not. I can't see in there and there are other bits of the body that may be in the way of the cone from forming to inside contours. Has anybody here made anything that keeps the rodents out?
