LSP vs LSPX and The Point


I need some advice.
I want to get a first edition of Harry Nilsson's, The Point.
The trouble is, I keep finding "first editions' for sale some with the LSP designation, others, with LSPX.
So what gives? What's LSPX, anyway?
And, for best sound quality, should I maybe be thinking of a UK copy?
Thanks.
128x128nietzschelover