Crosby's tune looks like an utter mess. It's recognizably in the "Banks of the Devon" family, but the mode is weird - dorian/minor hexatonic with sharpened leading note would be normal enough, but he sharps the seventh in descent. And there's a chromatic slide in the second part that seems out to lunch. I haven't looked through the rest of the book, does he ever display signs of competence?

The tune in Kerr is much more normal - first half stays in a minor pentachord, secold part is dorian/minor hexatonic. Modally simplified to the max. Kerr's market was dance musicians and it shows here.