Taking on-board the advice from KH1 and Middlepeak I had some further goes at the brickwork on the building. Running in some very dilute acrylic white into the mortar joints worked well and then I tried just lifting the colour of the bricks using some Derwent graphic pencils. Using a couple of different colours on the brick red gets quite a nice subtle variation in my view and I hope I've toned down the quions to slightly better grey-yellow of the Cambridge white bricks.
On Friday I also made a trip to the cutter and had a first go at the windows. I cut these in 1.5mm MDF and you can draw the glazing bars at about .7mm and still cut them. Careful sanding takes the depth down to about .75mm before painting and sticking onto some clear plastic.The result can been seen in this rather cruel enlargement (the actual height of this section is 50mm), at any kind of distance it looks pretty good.
Justin1985 asked about the drawing shown on the previous post. This was the drawings of Takeley, available for purchase and download from the GERS site.