The cardboard boxes take the inscribing well but you have to hold a piece of wood behind the piece you're working on it does'nt take as much time as most people think

just measure on the corners

and scribe a line between the marks with a piece of metal that gives the size of groove you want

then I use a screwdriver and steel rule to mark the end of the bricks.

I did'nt show the piece of wood being held behind because I was holding the camera
this is my progress so far

the first two stories of the center building won't have exposed brick.I messed up on the windows of the second story so that's a redo. any imperfections on the upper stories should be covered up by window frames and sills.