Help identifying this Lockshield (Radiator)

[Whoop]

I recently had to take my radiator off to fix a problem behind it and due to the age (probably - or someone over keen!) the top of the lockshield sheared off and I can no longer turn the radiator back on.

It doesn't seem to be a standard fitting though! The pipes are seem to be standard 15mm but I'm drawing a blank finding something that will replace the fixture -

Spoiler: And a rather blurry shot from when it was off

Any advice welcome, thank you.

 

[Whoop]

Looks like standard valve to me with plastic cover taken off and the broken top part xD
http://www.wickes.co.uk/Wickes-Radiator-Lockshield-Valve-15x12mm/p/421551

I wish, check the blurry second image. It's huge where it connects to the radiator.

 

[Whoop]

Thanks everyone, the key part seems to be changing the tail in the radiator.

I've looked at it a couple of times but it seems to be about as good condition as the valve and quite rounded! I'm sure some tool will manage to undo it...