I have a question about the UK 1st/1st of The Shining. I have two copies of this book. Both have the exact same copyright page (with no reprints stated), dust jacket, gutter code etcetera. And yet yesterday I found out that the books themselves (underneath the dust jacket) look completely different! How is this possible? Anyone have an idea? Is one of them not a 1st/1st? But why, then, is everything exactly the same except the boards of the books (and they also differ in size a tiny bit)?

I should add that the black book came with a priceclipped DJ. Not sure if this means anything in this context, though.