The camper I purchased is a nomad 14. The good is I'm positive it has a heavy duty axle since it has trailer brakes. The bad is it was advertised as weighing 1200lbs, but the local scrap yard weighed it at 2700lbs.....so its way too heavy in its current state. My explorer got 11mpg towing this parachute home. It does had a square stock frame that's 4'8" wide with triangular gussets that stretch out to the full width of the camper.
here's a pic:

The thing I'm currently chewing over is what would be the best base for a project. Scrap the body on this thing and build to suit, or the other option
I've been thinking about is taking the rear of a SUV like a jeep cherokee or dodge durango (which has a frame) and making that into a tear style camper (it would take engineering a waterproof hatch and door setup out of the equation but probably create heating and cooling issues with all the glass).
Weight of the finished product is also a concern, so until I get an idea of weights I'm stuck guessing. I'm shooting for 1500 max loaded weight, which is prob about 300lbs of gear....so 1200 max empty weight.
I'm planning on having a 24 inch storage box at the front of the trailer built into a V to use as much space as possible. I'm planning on outfitting it with everything I need for mobile summer living-propane shower, mini gen set, maybe a small a/c, wave3 heater, etc (hence the large storage box up front. 5x10 is that I'm shooting for, with 8' of camper, and 2 foot storage box. It will all ride on 35" tires.
So, given the pic of my current trailer, would you use this frame as a donor, or is it too heavy? Sell it and start over? I only have about $250 in it now, which is less than the axle would cost me. I'd also appreciate input on the SUV tub idea- that would come complete with hatch, doors, etc. Just have to outfit it and insulate....but it may be way too heavy.
Lots of good info here, I'm excited to get moving on it!