I had a Captain
trailer at one time, big brother to the cadet
. There was a half Inch wooden strip around the window on the inside which had velcro glued to it. The screens had velcro around the edge which stuck to the wooden strip. I replaced the screening material with something used for screen rooms - a bit heavier and more durable.
You had to pull the screening away to open or close the windows
but easy to do.
I honestly dont remember how the wooden frame was attached. There was wood-patterned masonite around the window on the inside and the wood screen frame was attached to the masonite. I'm pretty sure it was screwed on, not glued but don't take me to court on that.