After doing some research, I gave Hadlow Marine a call and spoke to Jean-Pierre. He suggested I could send him templates of the windows or send the windows to him. I thought accuracy it would be better if I had the windows couriered to him. Well, that was fun.... they looked even worse than my attempts at present wrapping! They did get there though and poor Jean-Pierre probably had quite a job to unwrap them.
Fitting the windows was a nightmare all of its. Thank goodness, we didn't have any silly plans to try and cut and drill them ourselves. If even one of the holes had been misaligned, it would have been disastrous. As it was, we had to contend with the windows needing different length inter-screws in various positions as the fibreglass is thicker in some areas than others. Frustrating at best as it meant, cutting some of the inter-screws to the required length.
We also made a rather frustrating (at the time) discovery. Whatever you do, do NOT try and install the windows on a really hot day. The acrylic actually expands and suddenly, nothing fits! All the screws that fitted into the holes the evening before, suddenly didn't align. As you can imagine, there was a certain amount of panic that accompanied this discovery! We ended up having to wait until the weather had cooled down sufficiently for us to fit the windows as they were bowing out so badly. Once the temperature cooled down, we were able to align all the inter screws and tighten them as recommended (not more than 30%, basically just enough for the Scapa tape to bed in).