Max's French voice actor (from the '99 dubbing) is Cartman.
Money, Dear Boy: This movie was made solely because the Beatles were contractually obligated to make a third movie. They learned belatedly that, since this was an animated movie that did not quite star them, it didn't count. They did like it enough to make a short cameo appearance, though.
The Other Darrin: Peter Batten, the one-time actor who voiced George, was in reality a deserter from the British Army, unbeknownst to the staff of the movie. When he was arrested for deserting, Paul Angelis, the voice of Ringo and the Chief Blue Meanie, stepped in to finish the rest of George's lines.