Two of these cards, measuring roughly 6-1/2″ x 6-1/2″ and cut in the shape you can see, are available.  One is unused (Grade: 1, $4).  The other was mailed from Cavtat (we did that ourselves at the post office), has a 5.80 Kuna stamp but no postmark, and due to its size has some postal battering around the edge (Grade: 4, $5).