Hey! Kate! Where have you been hiding all these years?

Anent the key signatures: that's a David-Glen-ism and he explains it in his Edinburgh Collection. The idea is that if you aren't playing the tunes on something with a Highland pipe chanter scale, you might be better using a different key signature, so he tells you what it is (he mainly had the piano in mind). Highland pipers are going to ignore it anyway, so they aren't any worse off, except for having the music squashed into a quarter of an inch less horizontal space on each line.

Gimme a shout if you're coming to Edinburgh sometime?