Thanks, James. I only wish I had done that on purpose.....
Here's a quick little SBS on how I just did a plaster lath wall that will be seen from the back.
Building a the wall in scale is done the same way as the old craftsmen used to do it.
First, I framed a wall with scale 2'x 4" lumber. I squared the wall over graph paper:

The lath was done with thin, pre-stained strip stock:

From the back, the wall looked like this with the lath strips in place:

Next, I applied spackle to the front of the wall with a styrene trowel, squeezing a little
bit through the spaces between the lath:

From the front, the finished wall looks like this. Since this side of the wall won't be
seen, I'll leave it like this. If it were going to show, I'd sand this side and apply a finish
coat of spackle:

The INTERESTING side of the wall is the back:

In some spots, too much spackle oozed through, but that's easily chipped off
with a toothpick after everything dries:

This wall will be placed in front of a window in the Arcade building that was sealed
off during an earlier renovation. Not a detail that will jump out, but it adds a little
more interest to the scene:
