From Readme
These tracks were found within a huge 15Gb torrent https://kr.bt4g.org/magnet/ee4b400d33ece0ced0c5c8f670fa3851080b4d7b
I have taken the best quality of A and B sides of the cassettes to make this torrent. Someone converted the originals to .flac and could have had a poor cassette player as there are some pops and tape noises to be expected for the age of the original cassettes. These files could be from the original white versions, there were whites first and blacks after, as the file info states they are from 1981.
You can import these into Audacity and check the difference to the most recent versions available, they are quite different in some cases, longer and higher pitch, less white noise, etc, but the general content is similar.
ENJOY!