Next step in civilizing the hunting trailer

[Missed-Em]

So, when I bought this Safari several windows were broken and I replaced them with Plexiglas which worked fairly well till a down-burst took out two that I had already fixed. Being tired of window replacements I permanently attached Plexiglas to two windows. Now SWMBO wants to be able to open said windows. Spotted one vendor with appropriate window glass for sale. How hard is it to replace with glass and which vendors do you recommend?

[Mtmanor]

It has been extremely easy to deal with Vintage Trailer Supply.
We've replaced 4 windows, all curved, and it did take some time to get the old ones out. The original seal and rusted screws had to be "coaxed" out. They went grudgingly.
We had to replace the closers, too. Wish we could just get the guts for them as the old ones just needed the interior parts. But glad to have it done. It's made a huge difference.

[Missed-Em]

How are the glass windows "attached" to the frame? The ones on mine had screws thru the lexan.