gobsow, my father & I made a fiberglass patch for the cab corner of my '54 when I was in high school. We knew where there was an AD truck with good cab corners, got the owners permission and made an impression of the corner with modeling clay. We used the impression in the clay as a mold to make a fiberglass patch, using fine mesh fiberglass cloth. I cleaned up the hole where the corner had been, trimmed the oversized patch and attached the patch from the inside using sheet metal screw and epoxy to hold the patch, then took out the screw and smoothed it off with a thin coat or two of filler. It looked good and lasted as long as I had the truck.
