Several of Pleyel's tunes were published in dance music collections from the 1790s on - William Campbell, Corri & Dussek, and most influentially Aird. Is the Pleyel tune people are talking about here the one in Aird volume 4? - it's on my website at http://www.campin.me.uk/Aird/Aird-v4.abc .

Song "ownership": this idea has passed its use-by date. Whatever function it may have had 100 years ago, what it does now is encourage repetitive lazy bores to repel newcomers to the folk scene with their three-song repertoires. If you can't learn something new, learn how to sing with conviction out of a book (it isn't that difficult) and use that. And if you've got somebody in your scene with a three-song repertoire, learn them all and pre-empt them till they get the message.