Publishing is just weird. My first two novels were written in standard British English while living in Ireland, but were first purchased by a US publisher. The result: spellings changed to American Standard. Later, when picked up by a British publisher they left the AmStand spellings because the main character was an American!

JT Edson is British, and writes westerns-- and the spelling (and word use) is all over the place. It's either damn poor editing, or a case of total confusion on the part of his editors in both the USA and UK.

I'm not sure Amazon will ship to the USA ahead of US publication dates as their distribution contract should preclude that from happening (this is to prevent "flooding" or "dumping" lower priced editions of the same book in the market; the same applies to US titles shipping to the UK).