There is one at Crewe that is open to the public, when I went ,there is a signalman there to show you all about it. You can even go below deck to see the frames work. It was most interesting. I have a photo which I will post later when I find it, a super wide lens is essential kit incidently
Ken Birch

Oh I have just remembered, there is also one at Barrow Hill too, certainly on big event days anyway, I have photos in that one too.

For those interested in seeing inside a Signal box The NYMR is currently building a replica demonstration box on Pickering Station.
I will post detail about completion as and when I get to know.

Inside of a signal box
 

For those interested, here is the inside of a signal box. Its Crewe No.1 box at Crewe Heritage Center