Hi Charlie thank you for your question. This is a puzzling odd shape. I'm not sure if the "V" is a letter or a miscellaneous shape?
If you can manage to get a close-up shot of the mark it would help a great deal. You are welcome to upload a photo in a follow-up submission. Any more information that might help us in focusing our research to a particular period or region will help. Any other information you may have already discovered and any other details that will help.
