Czechoslovakian music was very popular in Poland, especially Karel Gott and Halina Vondrčková.
And the Czech pressing plant GZ Records is one of the best in the world today.

The large central hole in the small 7" single was used to place the record in a jukebox.
To this day, 7" records have two types of centres, small hole and big hole. The big hole usually had a knock-out centre, which, when pushed out, made a big hole and allowed the record to be placed in a jukebox.

Thank you for your article!