So I've been keeping my eyes out on CL for utility trailers, old standy's that people might be letting go cheap, etc when I came across a woman that is selling a 17' Wide World trailer. Yeah...hardly a td but maybe I could still get some feedback? Pretty please?

She was asking $300 for it, I got her down to $190. Here's what I know after seeing it today...the good and the bad:
Clean title and new tabs and license plate
Tail lights work pretty good although the 2nd right tail light is not blinking....could just be burnt out bulb
The inside is a mess....seriously disgusting. (dirty) There is stove and fridge (not sure if they work) and bathroom with toilet and shower. On the outside two corners of the siding are coming apart and when I pulled it back I could tell there was rot there.
Inside there were areas where I would push up on the ceiling and I could tell there was rot in the ceiling. Not the whole thing but some areas. Floor didn't seem too bad aside from the bathroom.....bathroom was definitely the worst area. Some wall areas were obvious rot (not surprisingly the areas where the outside siding was coming apart) but most seemed ok. Of course until I tear off some siding, who knows.
When she plugged in power from an extension cord a light went on inside and the pump started up which was good news. No idea if anything is working off propane as there were no tanks.
As I'm listing all of this it's starting to sound like a joke but maybe this still has potential. I have pics but I'll hold off on posting them because I may just be missing the obvious.
I've already thought of gutting the whole thing, maybe even the bathroom (or at least taking out a shower) and I'm expecting worse case scenario that I will find rot in many areas. I'm pretty handy (remember the hot dog cart? ha ha) but I'm worried about replacing joists or ceiling beams, etc. After watching some videos it appears that trailers like this are merely framed with 2"x2"'s, some trailer plastic/aluminum siding is put on, and then paneling is put on inside. (with insulation)
What I really want to do is put corrugated steel on the outside of my trailer whatever it happens to be. (this size, a tear drop, etc) I may not cover the whole thing but I definitely want a retro look to it and I think it would work great. But because of my limited expertise, I'm not even sure how to do it with a unit like this. Of course it needs to be skinned and sealed with some type of siding before putting on steel but not even sure where to start with that.....anyway...veering way off course now.
That's about all I know at this point....thanks for reading everyone. I don't mind cleaning, scrubbing, repairing, building (or learning how to build) the things I would need to do to make this thing like home, but what I'm afraid of is running across something that needs to be repaired by an RV professional and getting in deep over my head.
It sounds like a deal for $190 but I'm seeing guys on youtube doing repairs on similar size trailers that were GIVEN to them and they are in better condition! Yike!