That big interview in Discoveries magazine in the mid-90's mentioned that Dino (who's the band's archivist) has copies of some of those including a alternate take of "How Can I Be Sure" that's in 6/8 time, why he's sitting on those we'll never know. My uncle who engineered First Take, Volunteered Slavery, Silver Cycles and a few other Atlantic LP's told me that, he said it was "substandard tape which wouldn't line up on the machine" also "dog **** on plastic film" was another term he used. He forgot the brand name. Apparently Ahmet Ertegen was getting kickbacks from the tape manufacturer to use it in the studio. Me thinks the tape manufacturer was Audio Magnetics which is from the late 60's and was pretty rotten stuff, their cassettes were the worst.