The boards come from White Rose and are excellent quality. Even I can't screw up their construction.
Both are now marked out in the 6-inch squares of the model of the model. At some point I need to take a jigsaw to the front edge of the left hand one, but that can wait a while as I measure everything up.
The good news is that the fit comfortably in my workspace, which is good news as I'll be living with them for a while.