the postlady was kind to me yesterday, delivering these early in the afternoon for me to enjoy before a long night at work.
a group of 6 covers, all quite similar, yet quite different.

and a clear shot of a single cover.

and the postmarks, which is what makes them different.
Belgrade, Serbia
Ljubljana, Slovenia
Sarajevo, Bosnia & Herzegovina
Skopje, Macedonia
Titograd, Monetengro
Zagreb, Croatia

While browsing delCampe, I have noticed several instances of these multiple cancels (mostly on the annual UN Day issues of the 50's), but this was the first chance that I had to snag all 6 at once. (and only 1 euro each!)