Unknown shower model - how to fix?

[JB-BJ]

Good evening. Our shower valve seems to have broken it's internals - rotation of the handle (which both turns on/off and sets temperature) now does neither of those things. After getting the shower stuck on, I've managed to stop the water, and after removing the handle etc am left with this below.

I don't know what shower valve this is. Is it possible to remove/replace the cartridge with what I'm presented with here? I've had a look around on youtube but haven't found any that look similar. I figure if I can get the valve out I might be able to identify it.

Thanks.

 

[Hugh Jaleak]

Spanner on the hex nut at the base of the spindle I'd have thought would undo the cartridge. For ID and spares try www.showerdoc.com