This was another part we were putting off as we have never used fluting pliers before, nor created a curved L-angle.
We practiced with a scrap L-angle first and it turned out to be much easier than anticipated. With the first one down, we went on to make one complete unit. After one was in the books, we sped up our process a bit by making all of the L-angles, then the reinforced pieces to match.
By the end of the work session, we had 6 curved doublers (in need of deburring and cortec).