This film has had for me a fascination bordering on obsession for details regarding the production, the editing and the missing scenes and what was contained in the original screenplay before Peter Sellers left. Therefore Casino Royale can be considered as remarkably prescient in casting almost every character in the movie as a 'James Bond' - during the climax a number of performing seals and a Typhoo Tea chimpanzee dressed in a tuxedo and wearing a toupee are identified as 007 - I am not sure about the seals but the chimp has always struck me as a rather nasty but hilarious visual gag at the expense of Mr Connery. Today of course we have had seven actors playing the role of Bond and the character changes his face almost as regular as that other bastion of Britishness a certain TV Time Lord.
Without 'Casino Royale', it is possible that the best Bond movie 'OHMSS' would not have been made. However, when this movie came out during Sean Connery's final 60's Bond adventure going head to head with 'You Only Live Twice' it became apparent that even without Connery the Bond brand still had box office potential.
The idea of more than one actor playing the role of James Bond would have seemed very whacky when this film was made - as Sean Connery was seen my many to actually BE James Bond.