Afraid I don't recognise the mark but I am intrigued by the part of the spoon not shown in your pictures. Are the ridges on the bowl either side of the drop the beginning of an old style rattail of the type normally found on trefid or early dog nose spoons? If so, this is extremely unusual but might explain the West Country suggestion. There are other examples from that part of the world that mix old and new fashions. For example, I have a Hanoverian tablespoon by Edward Sweet of Dunster that has a beaded rattail. However, I could not swear that this sort of mixing is unique to the West Country.
Hi agphile, Sorry the photo doesn't show but it is not a rattail. I shall try and get a photo of the back of the bowl so you can see. I have searched high and low and cannot find any attribution of the mark yet! This one is still a mystery to me so far! Kind regards Rhodri.