I've seen 3 discrete ones in the metal, and we're probably around 10 or so on the forum. It's pretty difficult to find whether there's a unique identifying reference as we haven't seen these in literature to date, but it will be 15-something rather than 11 due to the Cal 15 movement.

Great to have the back story from Filip there. Definitely seems to be a European watch - as well as this Belgian one, the 3 watches I have seen all had German provenance. Compare to the Shauntavia, a watch I have never seen in the metal, where we know at least some of them came from the Far East. Maybe not enough of a sample size to determine anything really, but for me anecdotally at least, the mystery dial has been more prevalent than the Shauntavia one.