Thanks all, these are great suggestions. I can't believe I had forgotten Prairire Lullabye! and Scarlett Ribbons. I don't know if I've heard Hobo's Lullabye, Catspaw. Is that one that's on the Trio CDs?
I'd love to hear Chocolate Ice Cream Song, Louie. Know of any recordings?
(And Stewie, yes, I knew that other thread was there, but it wasn't as specific and was getting pretty long, so rather than refresh it, I thought I'd troll for some more suggestions.)
I'll print this out before it gets too long and see which of these I can find.