After pondering how to best ensure the fit of the WD-602 brackets against the F-770 skin and longeron, I decided simply to use a drift pin to center the parts and then clamp them in place when centered. Although it would have been easier with a partner, the process was relatively simple and once clamped in place, the rivets slipped in with no problem. After fitting, I drilled the firewall all around the F-770 and F-772 skins. Drilling with Boehlube and changing bits a couple of times ensured that the process went without a hitch. After drilling the firewall, I drilled the WD-602 brackets and then began to work on fitting the F-713 auxiliary longerons. The bandsaw and a couple of twists of the longeron clamped in a vise had both pieces ready for placement and drilling.