So the technique I'm using is perspex bent to shape. Note this attempt was in the oven to soften the perspex. It didn't work but I've realised that I can score and bend it much more easily and with better results.
I've attempted a number of technigues to 'diffuse' the lights. Painted scratch brush on the left and Humbrol etch spray on the right.. Various levels of paint in the middle. Current favourite is painted etched perspex.