Michaelj west we had the same problem on our 2005 newmar Essex, M4503 they wanted 4100.00 for a new replacement thermopane window. we got from a local glass company a 3/8 laminated solid glass replacement, I removed the window and took it to them, so they could make a drawing for the company to cut a new one. the cost was 1700.00 and we had it tinted in a gold color. It took 3 weeks, but the great thing is it will NEVER fog up again!!! our window size was 52x52 yours looks the same as ours. the only difference is 1/16 of an inch in thickness.