He was a career iron worker / metal fab guy. My guess is he hacked off whatever mounting plates there were just to get it off whatever it came from, knowing he'd have to refashion them in some way anyways. I know he didn't build the chassis though. From what I collect, he purchased it in 2012. Knowing it was certified in 1996 tells me it wasn't his because I lived with him between then and 2012 and he didn't have it.