Hiding the semaphor machine

I'm using old-style Maerklin semaphores for my signals. The masts are attached to a dual-coil switch machine which is quite bulky. In station areas I managed to hide them between the tracks and lowered them into the roadbed.

However, Emsingen's entry signal A is out in the middle of the forest, and I do need the machinery to be accessible for servicing. In this case ended up fitting a sheet of styrene over the space, brace it with some wood, and cover the ends with stone sheet.

Placing the cover at the signal showed that I didn't get the cutout for the mast quite right and had to enlarge the hole. I'll put a telephone cabin in front of the hole, so that it's not quite as obvious. Yes, this is actually one of the triple-coil semaphors, so the cover needed to be quite big.

Test fitting.

Update 2012/05/13:

Cover painted and topped with a thin layer of fine sand.

I painted the base and topped it with a thin layer of fine sand. Looks much better than the stark white of styrene.
The telephone box looks way out of scale. I wonder if this was a N-scale kit...