Put it together today. I bent all the tubes to hit the target but one of the tubes couldn't cut it. When you bend a tube, the outside of the metal tube stretches and the inside shrinks. This one had hole in it so I patched it. The heat from welding changed the nature of the steel so it wouldn't bend right. Instead of shrinking uniformly, it did a little accordion number on me. I replaced the tube with the only spare I had.
This is without a question the most tedious aspect of the build. I scratched my head raw over the bends here. They need to come in at 45° and bend down at ~10° to fit over the stubs. As I said, I didn't have spare tubes of this size so I was really sweating the details. In the end, I compounded the compensatory actions and wound up with 18 1/2" clearance from the bike axle instead of the planned 16 1/2".
I need to tweak it some. There is some stress in place and the pivot is something around 1/4" off center. When I get done massaging it and get tacked together, I'll put it on the bike and see how it looks. I can shorten it up to the 16 1/2" dimension, I won't know if it's worth it until I test fit it to the bike. I'm really pleased this came out as well as it did. I'll probably save the bulk of the welding for when I have a lot of pieces to do. I need to improve my technique so I'll need to focus more on that when I get there.