About 4 years ago, on a road trip to Wisconsin, I stopped by the late Roy Nacewics’s place in Michigan to pick up some quality hardware. He was out of tank welting and he graciously took the time to run a few yards through his sewing machine for me. I believe at the time he was the only one using the original Ford pyroxylin material for cowl tank and fender welting. Since Third Generation has taken over, I assume they would be using the same original material. It does make a difference.