Article number: 19753
If you´re a completist it´s really time to get a boner now.. here´s a real HYPER MEGA RARITY or whatever superlatives that might pop into your head about this one.
A misprint, test print or so(in any case, it´s a complete and otherwise finished sleeve with a fully printed back) - as far as we know anyway, the ONLY COPY in existence and no one has ever seen or even heard of another copy(!) So get it while you can or be square - for the rest of your life..!!
See last pic for comparison with the normal sleeve.
Parlophone R 5452