Found on my favourite beach last week - the first I have ever seen - among pieces of blown 117 and 119 fuzes and pieces of 25 Pr driving band but is definitely nothing to do with those. It had remains of metal around the round shaft but difficult to tell what amongst the other crud I removed. My wife thinks it could be a button while I thought it looked a bit like a cufflink, however I think it too heavy duty to be either. It is made of brass and has a large slot in the rounded surface. Other weapony used on that beach includes 5.5 In HE, 18 Pr HE, small practice aircraft bombs, 2 In, 3 In and 4.2 In mortar, 20 mm Hispano Suiza HE and Practice, 2 Pr, 6 Pr and 25 Pr AP shot, i.e. all types are WW2 although it may be that the beach was also used as a training area in WW1. I've had the item rattling around in my pocket with my keys to clean it. It is possible it was fitted with a spring, such that a screwdriver could be inserted in the slotted head, the item pushed into a recess and turned but that is just a guess. It has no markings or stampings.
