Thanks a lot for the Turkmenish cancellations, @ChristianJ! If you are more comfortable in English, messages in English are fine, of course.
This is the best cancellation I was ever able to get from the Frankfurt landmark cancellation (the motif is supposed to be Hauptwache and spire of Katharinenkirche). When I was in Köln (Cologne) the same year, the philetelic clerk refused to cancel anything with the landmark stamp and proved it was really unreadable by doing a sample stamping (which unfortunately she refused to give to me). So it’s possible that these stamps have been removed or are hidden in the closet. Ask the clerk in Berlin when you visit again, I’m curious what the response is.
That’s why I intentionally call it philatelic counter, not shop. I’ve seen much better philatelic shops, for example in Prague and Zagreb. The philatelic counter in Frankfurt am Main is perched in a corner of the post office.