The Dutch foundation Bunkerbehoud has restored a cupola, the mounting mechanism, aiming circle and the periscope. The bunker in Flushing can be visited in the summer every sunday afternoon. Here are some pictures.
Fully operational in a bunker type 143, an artillery observation bunker.
The aiming circle is present and working properly.
Here the cable for the counter weight mechanism.
Some details.
Looking over the Scheldt estuary in 2006.