We heard this tune played by Kerfuffle (playing it here at 2:28 mins) and they named it Dr Letcher’s Favourite after having been taught it by Andy Letcher (Telling the Bees), but Jane, who actually taught it to us, says it’s proper name is Mounthills. Anyway, it is a good favourite. Here’s an almost unaccompanied version of Mounthills. And at 2:20 mins, here is Sam Sweeney playing it on his own (and including some variations).
In 2022, I’ve added (see below the alto version) the tune in G as well as C as it seems to be more often played in other local sessions in G and so it might be easier to learn it in a key that others use too.
Mounthills in C pdf is here.
If you’d prefer it in the alto clef, here you go (and pdf).