Used it on my '56. Followed how-to I found on the web
http://www.classictruckshop.com/welting.asp The key was the Craftsman Handi-Cut snips to cut out little pie-shaped pieces at the curves and the 3M #90 high strength adhesive used for gluing the material to the inside of the fenders before mounting.
The guys in the Midplains F-100 club that I belong to (I'm the only member with a Chevy truck) used a high-quality clear exterior sealer to seal the space between the fenders and the box--no welting at all. I personally like the look of the fender welt.
