My 1990 Shorlander bunk style trailer, is showing it's age, in the form of rust. Would it be better to purchase a new trailer or shotblast and paint the old one? Obviously, the shotblast and repaint would take care or the exterior, however, what about the integrity of the steel from the inside out? Your comments and help are deeply appreciated, as I get well informed info and ideas from this forum. Thanks guys!!!!!!!!