It's a good look and you've done a great job on it.
I found it easier to use 4mm balsa wood, shave off 1mm where the plaster is missing and cut the brick work straight in, using a knife against the grain and scoring a sharpened paintbrush handle with it. Then I just brushed on a bit of plaster and PVA where the 'plaster' was still intact. Balsa is far easier to cut to shape, and to cut out windows, doors, etc.
Just a thought.

