Quote Originally Posted by Henry Krinkle View Post
Interesting. What are the reference numbers on the case backs? I can't quite make them out in your photos. They should both be 11773, possibly / 1, 2, or 3. The The 11868 should be the day/date version.

In reference to the Marco Polo, mine had exactly the same vertical deep brushing on the case sides.
Yes, mine have both ref. 11773/2, ref. 11868 is the day date model! really uncommon to find.