You'll find below a picture of the sheet metal works done on the cab for my Chevy. I know, it's a GMC cab because the original one is very rusty and much more heavy to repair. On this cab only the back sheet metal and the corners need to be change. I drew with Autocad the exact shape of the rear rib and manufactured the roller beads by a machine shop. With these tools, I can to replicate on sheet metals the exact shape of the rib. The most difficult work to do was to reproduce the corners because we must to bend and form sheet on two axes of curves. After some tests, we were able to reproduce perfect corners and pictures will follow shortly.

Cheers