Found a bit of time today, so a short update.
Been messing with the IR wire/led.
Stuffed wire in some red heat shrink and found a little rubber O-ring in the box of spare plumbing stuff. The O-ring is just the right size for the led.
I can glue the o-ring to the inside rear cross member and it will hold the IR LED securely. Haven't glued it in yet. First have to figure out where the receiver mounts on the trailer. Might have to move position closer to the fifth wheel
Got a temp solution for running the wire, but not too pleased as of yet. Would like to combine it with the rear lights and the fifth wheel servo, but haven't got red tubing of that size ... Maybe run one tube on each side would work better.
Will have to run the wire through the mid cross member and hope it fits and doesn't interfere with the bowden cables from the differential and transmission already there.