I've got questions about the heater tube for my '66. I think the insulation jacket on it is in its original condition but I'm not sure. The outer most layer of the covering appears to be burlap on the section that gets hidden by the belly pans. The outer most layer of the section that is closer to the front appears to be vinyl. Is this how it is supposed to be? It looks like it is in pretty good shape but should I take it off and double check the condition of the heater tube? Should I replace the jacket with new, "improved" materials? I am more concerned with having a toasty ride in the winter rather than points at a show for being more original. Julie