G'day Andy, the whole thing looks really good. My only recommedation for this dio would be to give the wall a dull coat because bricks usually dont shine.
What materials did you use to do it?
Here is my first wall that I recently finished and is done in plaster.

If you ever get the chance, get some plaster of paris and give it a try. Sculpting is really easy and you can give it about any shape that you like. This is mainly what I do:
1) Sculpt the wall out of a panel of plaster
2) Coat the the plaster wall with future (klear) varnish to stop the dust from getting off the surface
3) Paint everything. Take into consideration using different tones of brick.
4) Future coat to give it a glossy look (needed for step 5)
5) Oils (burnt umber + black) very dilluted
6) Flat finish (needed for step 7)
7) Pastels to simulate dust
8) Flat finish
The rubble stones are pieces of plaster. I just got a block of plaster and hammered it down to pieces

FUN. Then, for the smaller pieces of debris I improvised. Get a considerable amount of plaster dust (from the hammering) and put it in a bowl. Then pour some future into the bowl and mix. This goo that you get can be placed all over the paviment, and when dried it gives a really nice look.
Zverko