Don,
Simple is good. The plan is for the Loksound Select Micro to mount right on top of the motor housing (using foam tape) so your wiring "switchback" would work. Course, it may take a 2-3 switchbacks to allow enough slack to lay the shell on its side.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.