Hungarian composer Emil Petrovics wrote his first string quartet in 1959, Lutosławski wrote his in 1964. So both these works are from around the same era. Petrovics was totally unknown to me, but the liner notes describe him as the foremost Hungarian composer of his time, best known for film and incidental music. I suppose the early 20th century was a time when many classical composers dabbled a bit in film music.
Petrovics wrote second string quartet in 1991, well after this record was released. Both quartets have been recorded in 1999 by the Bartók String Quartet. I have not heard that recording yet, but I must say that for a recording from 1977, this one is quite good. I was able to find the Lutosławski on Spotify, so it might be interesting to have a listen.