I posted a request for help on this topic some time ago. The outcome was that the window frames are complex, have 3 separate seals - one of which is captive in the frame and not replaceable. A company in Denmark (http://www.ertec.dk) can supply a set of made-to measure replacement windows and frames at a cost of around £1,800. Part of the deal is that you remove your windows, measure the thickness of the saloon sidewall and report this to them. They make it up and you install it. Well, this did not sound attractive at all. So I carefully masked both the frame / boat joint and then the window-frame joint and separately applied black Sikaflex. Not pretty on close inspection, but with care and at a range of a few feet it looks just fine. And it works! Not a drop getting in. About 6 hours work. Cost - one tube of Sikaflex, 2 rolls of masking tape and a kitchen roll. And sore knees. Barry