Tonight, I bend all of the battery box flanges. First I bent over the "lip" which makes it easy on the fingers and also provides stiffening.
I then bent the bottom flap and the rivet mounting flange. To bend the first side, I used a corner of the workbench, and bent the metal down over a metal straightedge. Since two sides were now bent, I could not use the corner of the bench to bend down, but I could use it to bend "up."
With a helper, I found a workable spot in a bit and up a bit from the Sonex plans distances. This location allowed me to insert the battery with the mount installed with no problem. I could have used the plans-spec'd distances, but that put the positive post of the battery just a bit closer to the metal throttle & mixture cables than I wanted (see the red dots in the upper r/h corner of pic 3 below).
