Just started doing my own windows, too. When I picked up the unit from the P.O, he indicated that the windows needed resealing. The other thing that popped out was that the window with broken operators (a known problem, fwiw) happened when they went to Florida last year. He gave me a box full of gaskets and wished me luck.
As it turns out, none of the gaskets fit the windows. Turns out there are a bunch of different window sealing systems out there. Steve at Airstream Dreams really seems to be the best expert. That's why Vern (aka, 53 Flying Cloud) is asking for pictures. We can't really help unless we see what you are dealing with. I'll be posting pictures to my blog shortly that I've made of my effort. But I don't think it will necessarily be what you will face.
By the way, the problematic window ended up entirely sealed with silicone. For us, the system is that there is a sticky strip of mastic against the frame, then the window, then a gasket that wedges it all in place. The frame I'm currently cleaning tells a story of an epic road disaster. Silicone layered in, in many colors, then the glass, then more silicone. A broken frame. Stripped operators. Bad time in FL, I'm afraid.