Your other option: You will find out like I did that if you try ordering a new window from Hehr, or most other manufacturers of trailer fit windows
the price they want will truely knock your socks off.
Resellers, salvagers, etc. have them on ebay. I was able to pick up 3 virtually brand new, replacement windows
for my 13 ft Burro
on ebay for a fraction of the cost. Only problem was they did not quite match up with my rough openings so I had to do fiberglass surgery to fit them. But I was prepared for that, did it, and now have no worries.
Have patience, keep watching, and get lucky.