P.S. It was 50 hours of "...tapes weren't really lost, but were left in the cupboards of the studio archives for so long everybody just forgot about them. Everybody except Hildegard....". This excerpt is from the liner notes by Irmin Schmidt, her husband. Good story.
Also, sorry about earlier advice. I checked Discogs and the vinyl prices gone thru the roof. Maybe some other medium/medias would work.