Welcome to the club! The bad news is that the manuals for each of the old trailers are almost unavailable -- the good news is that they were worthless anyways, with bland generic info.
The best news is that manuals for each of the subsystems (air conditioning, heater, fridge, etc) are all available online. Just find the model number on the unit, type it in, and you are all set.
Congratulations on your new RV! Your son may not yet realize what a lucky guy he is, but someday he will.
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)