I think the first time I saw George at Ronnie Scotts was either just before or just after that 'Amsterdam After Dark' LP was cut - the quartet played most of those tunes. Pretty memorable it was too - George's circular breathing was astonishing. Either the next time or time-but-one he was at Scotts it was with the Octet (Frank Strozier, Danny Moore, Mario Riviera etc). They cut a disk that week on Ronnie's own label - not sure if it was the 'Big George'.
Big George is an American record. Although I have it on the British Affinity label, it says it's a Catalyst Recording, recorded in NYC and mastered in Hollywood.