Bob:
I don't know who made the window, but I had fog and a bad case of creep in my 1999 Tradewinds when we bought it in 2015. I took it to RV Fog Dr (Searcy, AR) in 2016 and they fixed me up! And, for a whole lot less than a replacement. They reused everything, frame, glass & screws.
Here's the before picture (2015):
And here's the after picture (2016):