I am doing the Poly Fiber "Island/palm tree/rabbit" stitch now. It works under the tank, using the curved needle, if you can't get to the inside for...
I color code, and use shielded twisted pairs. I don't do it professionally, so need to keep track of which wire is signal and which is return inside...
I have a lot of experience with that. For right now, the best solution in a J3 is a Garmin GTR-200, mounted in the wing just ahead of the rear spar,...