Al Stuber put his CH 750 project on hold long enough to drop by and hold the bucking bar against the belly skin while I crawled inside and backriveted the transponder doubler. Thanks Al.
The brown discoloration in the above photo is alodine, by the way. Don't want any surface corrosion forming here and messing up my antenna ground plane.
Here's a shot of the transponder antenna bolted to the bottom of the fuselage… nothing to it, just a plastic shark fin thingy:
One more thing checked off the to-do list.