Not certain how the tool will work on the upper staples, since that is a tighter reach due to the long flap. The original machine that GM used was a large electric stapler manufactured by Bostitch. When I worked in a shop back in the early 1960's putting together boxes, they had one. It used flat staples, unlike the ones GM used, which were round wire staples, but the machines worked the same. This is the same type of machine that the companies that make up reproduction door panels, use to attach the cardboard to the top metal panels, and also the inside the weatherstrips...