Perhaps the gnomon (pointer) on some sort of ornate sundial? One thing that bothers me about this theory is that hole in the fin. What is it there for? and it's quite short, which makes me twitchy too.
I didn't post that earlier, because I didn't want to clutter the whaling implement story.
The thing I don't like about the whale sticker interpretation is that toggle harpoons are old. If it's supposed to take the strain of raising a whale carcass, you'd expect either toggle barbs or something similar that would stick in the body.
Best,
F
P.S.: I know what it is! Stonehenge and other standing stone circles are just really old silicon-based astronomical computers. Maybe this is just the cursor for Stonehenge's graphic interface.
