had he already quit bond by this stage or was he moonlighting?
Apparently this film - based on a stage play - was one of the things that United Artists had to fund when he returned as Bond for
Diamonds Are Forever. The other was an unproduced version of
Macbeth of all things.
With all due respect, that doesn't strike me as that strange. A Scotsman (Connery) playing a Scottish king (Macbeth.) How many Scotsmen have played the king? I have seen Maurice Evans, Jon Finch, and Orson Welles play Macbeth, and none of them were Scots. Both Evans and Finch were English, and Welles was an American.
As a matter of historical note, there really was a Scottish king called Macbeth, and his portrait, I believe can be seen at Holyrood Palace, which I have visited, in Edinburgh, Scotland. And while the reign of Scottish kings at that time was extremely short, his was one of the longest ones at that time, which gives historians the belief, that he might not have been that bad of a king to survive and rule that long, especially not as bad as Shakespeare makes him out to be.