Though I'm a guy, I'm not trying to take sides. I would have to agree with your soon to be "Ex" on this one. A trailer that is gutted is a project, sometimes parts are missing, etc... Like many folks before you and there will be many afterwards, money was spent in the wrong place upfront (polishing) if left outside, it will need to be redone again by the time the trailer is finished, hince not adding 4K in value to the trailer.
I've bought many trailers in my day and I even own a 1966
Overlander, unless the skin is in perfect shape and all the cabinets are in perfect shape, you are talking a 2,000-3,000 dollar trailer more towards the 2,500 number.
It's sad when this happens, not only to couples but trailers and even worst, it happens all the time. Hope the two of you can put everything back together including the trailer ;-)