The WH-00046 cable forward of the F-1203A bulkhead grommet is in final position. Working the cable further aft, slowly but surely.
Discovered an unexpected, but welcomed surprise. The RV-12 has an external audio jack! … it is located between the seats on the F-1203A bulkhead. Knew there was a 12 volt cigarette lighter type of a power source in that area, but did not realize there was also an audio jack for connecting an MP3 player or other audio source.
Auxiliary audio jack in my hand goes into the hole my finger is pointing to. An unexpected nicety.