George Orwell's First Editions are  difficult to find for a few reasons :

1.  He was never really popular in his lifetime, not until he wrote 'Animal Farm' did people  begin to take notice of him, and consequently the print runs on all his early books  was tiny.

2. Due to wartime rationing  the quality of paper used for both the book and the dust jacket was very poor and would quickly disintegrate,  especially in libraries.

3. Signed  copies of his work are particularly rare, he didn't to my knowledge do any public signings,  so the few signed books that do appear were  usually signed for friends and colleagues  making them even more valuable,   

Mostly Orwell's  First Editions were the UK editions apart from one .

A Brief Word about Rebound Leather Editions,  and this is only my humble opinion,   Don't buy them.   As soon as the cover is removed and the Leather is stuck on they cease to be First editions. They will never be worth more than you have paid for them in fact,  they will probably go down in value.

     Unless of course this is a special edition put together by the Original Publisher at the time of the first edition and this  never happened with any of Orwell's works.