I believe they were water jetted. A friend owns a metal fab. I got the aluminum plate to him with the drawing and he cut it.
I never asked what he specifically did.
they turned out better than I had hoped - everything bolted up perfectly, the mount is rock solid. There's a aluminum angle mounted on the back side that is also bolted to the cross rail.
the "A" sits on top of the bar and is bolted to the side rails. then the angle bolts it to the cross bar. no movement in any axis that I can detect.
I'm more than pleased with how they turned out. Simple is good. They're rock solid and meet my needs perfectly. I wanted something I could adapt to multiple uses. The "A" shape came out of a lot of time spent drawing and cutting out cardboard shapes.
They work for both the jack and the axe/shovel mounts.
now I'm thinking about jerry can mounts. (but I'll probably do lights next)