Howdy,
The military uses a 24 volt lighting system. The military uses a special vehicle and trailer plug. There are threads here with information about making changes. I myself have cut off the military plug and throw on a cheapie RV 7way plug. Yes, you are only using 4 wires. ground, left and right turn, and running. All the bulbs will also need to be swapped out to 12 volt bulbs. Other have said, to get it home, harbor freight has a quickie trailer light set which you simply plug into your truck and zip tie the lights onto the end, and zip tie the wires down and be on you way. You need to go to the pickup prepared for the worse. Tires flat, safety tow chains do not reach, lighting, brakes, axles, bearings, can it be towed home? or on a trailer itself home?
Either way, by looking at what you got. The unit looks good with a recent reset. I do not think they swapped out the hour meter. By the looks and running of the engine, there is no way that engine has almost 6000 hours on it. At least your inspector knew what they were doing. Good all around pictures, even showing the unit starting, and changing the ammeter to show single phase. Be careful about the exhaust cover flap. We are having some good rains around here the last few days and short future before you pick it up. At least you know it starts and runs.
Trailer = It looks because of the reset, you have that unit on a newer trailer. The tag shows a 2010 trailer. incandescent or led bulbs? I do not know from the views.
Pintle , lunette height = If the height remained the same from M101A3 trailers to the M1102 type trailers, the height is around 25 inches. There are some forum threads about truck connections. Here is my thread about a 2007
LTT-TQG lunette and pintle height info
Engine = looks good, you will want to pick up some 3.5mm yellow stripe fuel return line. Your fuel return line is weeping.
Fuel return line thread
good luck