I never saw Jocko build a body. He was in the same building as Doug Kruse, though. I worked next door. If he did, I bet he didn't do it alone. Kruse (pronounced cru-sy) gas welded AL, never TIG'ed that I saw.
Jocko was brilliant, no doubt. He died still working on his famous engine idea. To even think that siht was beyond belief. One thing folks don't know a lot about is that Jocko made wood sculptures and was a name in the art world.