The Parent Trap (1961 David Swift & scr)

Based on the silly book 'Das Doppelte Lottchen' (1949) by Erich Kästner (would you really separate twins?) which by this time had already been filmed in Germany, Japan and the UK (in 1953, written and directed by none other than Emeric Pressburger under the name Twice Upon a Time! - now missing in action).

The two Hayley Mills are fine, supported by Maureen O'Hara, Brian Keith, Charlie Ruggles, Leo G. Carroll and Joanna Barnes as the other woman.

Interestingly, composer Frank de Vol has a small part, and it's shot by Peckinpah regular Lucien Ballard.

It's quite long. i think I would have cut / reduced the girls' original antagonism to each other and the cringey pop song, but it sort of picks up in the last half hour.