RonR,
I understand your concerns with trailer lights.
Superbright LEDs had almost all the side/marker and rear lights for my 54/55 6v (positive ground) COE flatbed.
The only lamps they did not have were various bright, mutli-LED lights/lamps, like back-up lamps (they might have them now).
https://www.superbrightleds.com/search/led-products/6v+led/Also, there are dependable and inexpensive 6v to 12v power-converters that work quite well and reliably with 12v leds. The LEDs are easy power-draws for any voltage converters.
