I'm really considering getting the fiberglass fenders instead of straightening the beat old fenders. All the compound curves on the old vehicles makes for some very challenging body work. I agree with the breathing issue, I have a home made remote fresh air supply but it still is not perfect, I think it drys me out and maybe a little fumes still get in around the mask. When i used to use a filter mask the smell was really powerful, not good. Then there's all that bondo and primer dust too. How do people do it for a living?