WW1 Relic

I'm not 100% sure what this is from or even which country made it. At first I thought it was British, and I'm pretty sure it is but it doesn't have the War Department 'Crows Foot' mark.

What I do know is that I found it on the Somme, on the outskirts of Albert, in the early 90's and it took a lot of cleaning to bring it up to it's current state.