I've trawled through a variety of both members and non-members contributions re back stamps for Edinburgh Crystal Company, although can't seem to find this particular one. The piece in question is a vase with fairly straightforward cutting, and date wise I am thinking somewhere in the region of 1940 - 1960, although might possibly be a little earlier. So grateful if someone does have a more definite and accurate idea please, and thanks for looking. Believe the mark is acid etched, and before I could get an image that the camera could 'see' I gave the mark just a feint rubbing from an ink pad, which is why it may look a little dark. Actual stamp is about 11mm long.