I've started work on the truck again, and the current project is to combine a pile of junk fenders into 2 good fenders. I'm using the rust-free but badly mashed passenger fender I picked up at the flea market, cutting out the damage and replacing it with a piece from my rotted out original passenger fender.
First I cut back all the mashed metal, then came the tedious process of fitting, trimming, fitting, trimming.
I finally got to the point where the upper portion was as close as I could get it, and I couldn't fit any further because the whole thing kept shifting. By this point I'd mis-cut part of the lower section because the whole thing would shift while I was trying to eyeball cuts. So I got the top lined up and tacked it into place. This way it is stable to trim the bottom part. I'm planning to bolt it to the grille support panel upside down on the bench so everything is held in place for me to do the final fitting & welding of the lower half.