I'm not the world's best ABC sight reader, but I recognise that morris tune also sung to the words "Oh dear Mother what a fool I've been/six young lads came a-courting me"...etc. and used for an Adderbury Stick dance.

Not the same tune, but of course there might be all sorts of reasons for calling a tune The Twenty Ninth of May.

I suspect the confusion with "The King Enjoys His Own Again/World Turned Upside Down" is down to somebody simply misremembering which tune was which, not anything more academically interesting. The last two bars of each half of the tune are slightly similar, but IMHO they are not the same tune.

Anahata