I guess it's due to different thermal expansion rates or just being a bit crap.
Fortunately my local Hackspace has a nifty mini milling machine and a box of acrylic offcuts from the laser cutter. So I gets busy.
Alas - after replacing the window I needed to wet & dry the front and polish it all up to get everything looking flat and like new. It was all looking like I would need to spray the thing.
But £8.20 later I had a better way (following an hour with a ruler and Adobe Illustrator) - a neat vinyl sticker to wrap the facia in. It turned out ok. The corners were never going to be straightforward but transport vinyl is quite stretchy.
Here's a link to the file that made this - the left and right clock windows are a smaller by 2mm top and bottom but the signmaker guys can fix that if you don't need to crop because you didn't mess up when gluing in the new windows. This file is a line file just for the vinyl cutter to use.
http://www.mememedia.net/falco2/FalcoDashMask.pdf
