Well, I want to see if I can eke out a little more detail from the outside model. It might get a little bigger, so I can fit a teledoor inside it, and link it up to the control room.
The awesome thing is that this is really economical on bricks so far- the control room is 361 bricks and fits exactly on a 32x baseplate. The police box is 31 bricks, but as I said, I may rework it and scale it up slightly.
Since it is so light on brick count, I'm thinking of also adding the original cloister bell.