Given the sheer, bewildering volume of recordings in Bob Dylan's vaults, you might think there was nothing left to uncover in his discography. But as one lucky collector recently discovered, not even the most ardent Dylan traders have heard it all.

ABC News Radio reports that a vinyl enthusiast named Jeff Gold is the proud new owner of a stack of vintage Dylan acetates -- 149 in all -- containing works in progress recorded during the sessions for 1969's 'Nashville Skyline' and 1970's 'Self Portrait' and 'New Morning.'

As Gold explained to the collectors' site RecordMecca, the recordings were stored in a New York City building where Dylan rented a room he was using as a studio. It's believed he simply left them behind when he moved out, and they've remained undiscovered until now.

Gold has placed a few selections from his find up for sale at RecordMecca, with prices ranging from $1,750 to $7,000. Of particular interest to collectors are alternate and unreleased cuts including electric versions of Johnny Cash's 'Ring of Fire' and 'Folsom Prison Blues.'