To be young again. Do I understand you will not have an electrical hookup. Gets dark alot up there in the winter. Rivet lines tell you where the ribs are located in the trailer walls. The trick will be cutting a round hole in a bent surface. The flatter the area the better. I like the window swap idea as it gives you the spring time option. If you remove the window find out what the trick is for your particular year. Cann't imagine needing an additional source of heat with a woodstove going in a trailer. You are likly to end up with a sweat lodge and have to sit around with little clothing on.
