My buddy owns an air duct cleaning and heating cooling business. He has a large break/bending press. They form and bend all of their own duct parts. Maybe try one of those type of companies. (Sorry I didn’t get what you were getting at in the original post).

-Steve B. (WTB: 48" Flying A button, 48" black/org Phillips 66, White Star, and Chevrolet Signs. Also looking for a Wayne 866. Send a PM. Thanks.)