the metal is probably thinner than a beer cans metal so there is no chance of welding.  I was also thinking of trying something with some sort of epoxy.  The window won't be an issue cause I am going to bob it in the section where the rear window is and that window will just slide foward and should be perfect.  If not I will just take them both out and put in a piece of plexiglass or cut the one piece a little

....but if you every try to sleep in it without the sliding windows it can get real warm, take a good look at the frame there is usually a seam that you could use as a cutting point on the other side and then you could pop-rivit it back together with a small piece of what you cut out.