Research and measuring. Finally think I figured out how these things are supposed to be attached. Drilled and riveted on the stainless steel brackets where the leading edge areas attach to the tail boom tube. Then, on the offhand as I was about to take the picture of the pair, I found the horizontal tube of the LH to be about 1/2" shorter than the RH, which would explain the odd angle when I was attaching the elevator and hinges. So.. I will buy yet more tubing to fix yet another mistake I have made. I have enough tubing to fix the inboard tubing but not enough for the leading edge. I may also have to make new cross-braces, I have extra of that too, thankfully.