need replacement bedroom escape window

It sounds like you need to determine the manufacturer of the window unit and sizes. Then you can check suppliers like pplmotorhomes.com or the RV salvage companies listed on Google to get a replacement sent. For the salvage yards you may be able to find the same model of RV that you have and just tell them which window you need....trade photos with them along with dimensions to make sure you get the correct window.

For this weekend I would sandwich two pieces of plywood together, one on the inside & one on the outside, with a couple of bolts to tighten the pieces together, to cover the opening.