I should point out, in fairness, that Bruce does raise concerns about the Belgian Casablanca's release date:
The poster offered here is NOT printed on the back of a map, but it is the small size Belgian that we have only seen on Belgian posters from during and right after World War II, but it is possible that the movie was re-released in the early 1950s, and that they printed the posters from the exact same plates, which would account for the smaller size. Please do not bid on this poster unless you can accept the uncertainty as to its year of origin
However, the point of my original post centres on the use of marker on the poster as a means to further support a release date well more recent than even the 1950s.