IIRC, the working zipper was only available on a limited number of the original albums because of the expense of manufacturing the covers, as well as the problems with censorship and packaging (no pun intended) problems caused by the metal zippers; they caused damage to the albums themselves, as well as to albums shipped or stored in front or behind the Stones album...
I do recall not a few of my girlfriends and lady friends being somewhat very captivated by the zipper when they saw my copy of the album...
<O>
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