Welcome aboard Mitch.
Sorry, I can't help with your project, but hopefully others will be able to offer assistance.
Interesting background...I can relate somewhat to your R/C airplane business, though the R/C business has changed quite a bit from the 70's and 80's when I built and flew R/C airplanes.
2016 Winnebago Micro Minnie 2106DS, 200Ah BB, 400w rooftop solar, Renogy 2000w inverter
2020 Tundra SR5 DLCB TRD Off Road, 5.7L V8 w/6.5' bed & 38 gal. tank, 4.30 axle ratio
Blue Ox Sway Pro w/750# bars, wired RVS rear view camera, Renogy 20A DC/DC charger