When I originally built the superstructure I had no intention of 'furnishing' the inside so I did not cut out the windows. When I restarted I could not remember what I intended to do. Instead of starting again I decided to cut out the first layer of ply, paint the cleared window araea matt black, and then fill the 'gap' with 'glazing'. I then cut ot the 'frames' from 1/32 ply, not easy, the plasticard would have been much better. Also I stuck them on before painting them, so will need a steady hand or much masking when I come to paint them. With hindsight I would probably been better off starting again , but I suppose this is called the learning process.
In the phote the protective film is still on the 'glazing'
Howard