After measuring my glass channel dimensions to verify that the product would indeed fit I went ahead and ordered a fuzzy window track liner. It is offered by Vintage Trailers which is where I placed my order for VTS-278 Fuzzy Glass Channel for Airstream Classic & Revcon MHs
Research turned up this material was also used in the 1960's and very early 1970 as auto window glass run channel. You know when you rolled up your car window it went into that lined channel along the sides and top that sealed out the air and kept it from rattling. This stuff is the modern replacement for that era. Because it is also an auto window glass part you can purchase it from J.C.. Whitney as well but it is only a few cents cheaper from them.
I also order one more part, on the upright divider that is on the inside of the window there is a fuzzy weather strip piece. When I took the aluminum divider out to get a good look at it and touched the material to check its condition all the fuzz fell off onto the floor. It is another one of the universal auto glass materials but it too was used to make trailer windows.
That material is Vintage Trailer Supply part:
VTS-277 Pile Weatherstripping for Airstream Classic MHs
This is going to be an expensive rejuvination to get those windows functional again! So far just for this one purchase it was a little over $80.00 plus shipping. Of course I still need the outside gaskets and there is the cost of butyl tape as well.
Plus I need to fabricate a spacer ring for the inside. I had removed the felted wall liner the other night. There was an additional piece of material used in a ring right under the clamp frame. That material was just the old style grey felted carpet padding one would have found in a home. Not sure what I will make the spacer from, maybe one of the pieces of plastics we have lots of scraps of in the workshop. It can be cut on the tablesaw and it won't rot the way plywood might if a leak develops. Good to use up scraps and have it turn out better than new