Rob
I posted this in 2008 on the other side ,stalled at the moment as my interest moved on to a class 22 and class 15 plus other projects none of which I have finished much to my dismay.
Building a small 7mm MPD based on Kings Lynn (sounds familiar) for my local club at the moment (will get the camera tomorrow) then finish the Class 15 and then the Western .


From memory white plasikard base with 5thou black backing piece and square strip to form the raised edge . If PH produces an etch will go with that as a replacement .