I did some additional forming on three parts which were annealed yesterday, then put them back in the oven to anneal again along with another strip of -T3 material to make another attempt at the right side part. While those were cooking, I spent some time tweaking the my first attempt at the right side part. This is the one where both the flat and the curved flanges were formed down to the form block. After tweaking, this part is a very good fit. I may end up using this one after all.

Another view, more directly from the front. Nice uniform gap to accomodate the additional layers.

Very strange. The three parts I just annealed experienced blistering near the ends. I'm not sure what caused this. The flat piece of strip which was also in the oven at the same time did not experience similar blistering. The only thing I can think of is that these were in the oven in an orientation where the inside of the angle was facing the heating elements. Maybe it acted as a corner reflector causing excessively rapid heating of the surface.

Another view of the blistering.

I used the newly-annealed strip to form a new part for the right side, then put it back in the oven to soften it back up.