Ok, well it was not one of the greatest mysteries of all time. Certainly not an Agatha Christie novel, but, I found out what this morse key actually is. The key itself was easy enough, its a PMG key from WW2, it was the base that I could not find anything about on google. Anyway it turns out that it was a lantern signallers key from WW2. Use for short range communications on the battle field and came in a metal case, with a battery and a hand held light. They are pretty common and not worth a lot. But, still an interesting bit of history none the less.
Here is a picture of one in mint condition, all bolted into the lid of the box that housed the battery and light.