[jbjb]

Originally Posted by issybird

I'm sure; I read the pronunciation in a British book about Britlit between the wars. I don't doubt it's specific to him, or the point wouldn't have been made.

And.... this site agrees with me.

https://www.wikiwand.com/simple/Compton_Mackenzie

We'll have to agree to disagree over that one . He's of Scottish background, and I've lived most of my life in Scotland and never heard the "Cumpton" pronunciation.

I'd also choose an Oxford dictionary's pronunciation of a British name over that from some random US-based website! Again, I suspect that "Cumpton" may be an American corruption - maybe correct in the US, but not in the UK, and not how he'd have pronounced it himself.