Today I remade the T12-03 part that I messed up on 8/9/2011. It turned out great. I wish the plans for this part were full scale because I think it would match the plans within a 32nd of an inch.
I used my router to cut the sides of the flange. I played around with a scrap piece of metal first, until I was satisfied that I discovered all the "gotchas" that the router might cause.
When I didn't cut the 48" U-channel to size until I finished bending the flange at the end. This way if I messed up, I would only have to cut of about 1.5" and start again. Fortunately I didn't have to start over.
