My cab and hood were really bad on my 71. The roof of the cab looked like a bird bath. I tried hot water, hair dryer, and nothing worked. It was to the point that I had nothing to lose. I used the stove top and turned one burner up on high. I started with the cab and held it at a slight distance above the heat. When the plastic got just soft enough to work with I reshaped it. Don't get the plastic too hot though and be careful not to get burnt. Both the cab and hood turned out fine this way.