Faye, back in the Czechoslovakia under commies, the publications were done on the xerox or some kind of hard film, that was like scroll because they were not cut or assembled into notepad format (around 1975-1980). Later they came printed on yellow paper without pictures in small A4 notepad format. However, I remember books were always bound with pictures as far as 1970's and blue cover. My mom has these WT printed on yellow paper bound, because over time the were falling apart for that reason. I believe she has these on the xerox foils in her basement in the box if they did not fade completely. Last time I was at her place, she still kept my WTs from 25 years ago with my notes in it and she tried to leave them with me. Wasn't sure it that was an attempt on her side for me to see what I have missed or not.
During the 50's JWs depended on books published immediately after war and prior WWII. In Czechoslovakia, JWs were legal in interwar period as it was parliamentary democracy, and immediately after war until communist takeover in 1948. JWs were outlawed later in 1950 during the crackdown against all religions under Stalinist regime. We had one old JW who had these books visible at her bookshelf like Harp of God printed in 1920's and entire Rutherford collection - all in Czech language, but she never allowed anyone to read it or borrow it. During liberal 1960's and under Prague Spring events, communist regime tolerated JWs and I do not remember ever my mom had issue with the regime for being JW.