Decided to fill the crescent hole in the right-side rear canopy bow oversized hole with and "eccentric washer" fabricated as follows:
Cut off the head of a 3/8" bolt: centered in the 4-jaw chuck and turned the grip down to 5/16" dia. Faced the end square. Deliberately decentered until TIR= 1/32" (0.0625"). Center drill and used twist drills to gradually sneak up on a 1/4" bore.
The last size (D = 0.2460") broke out of the side 1/4" in, but no matter. I filed the ugly distorted knife-edges from the breakout, then sliced off a crescent from the end with a Dreml cut-off wheel. The crescent's thickness was a little thicker than the canopy bow weldment.
The crescent of steel--i.e., the eccentric cam, fit the grip of an AN4 bolt nice and snug, and in turn fit into the 5/16" dia hole in the weldment.
Drilled a 5/16" hole in a scrap of steel sheet and riveted it to a backing plate. A few strokes with a vixen file brought the eccentric washer to final thickness. Woo hoo!
