Both side windows are leaking. THere is a central plastic section that is broken on both sides, it may also be the seals that have gone. I was just enquiring if they are still manufactured
1987 DG 1900 petrol plus Yamaha Midnight Star and Yamaha Virago and !979 Vespa P125X
I no longer have an autosleeper so cant look at mine to try and advise you. Doubt they are still made - guess windows in modern vans will be different. Yours are sliding opening ones. If you search ebay under something like VW T25 autosleeper window, you will find someone is breaking an autosleeper. Their windows are fixed but if your damage is bad then changing to fixed might be an easier repair for you even though you might need new seals? The seals on the autosleeper being broken are probably damaged but worth asking about them?