To answer my own question, I ordered the book. Lyle himself uses a low G, but he expressly indicates that the tunes are meant to work With either a low or high G. I’m currently working on his arrangement of Edelweiss and it sounds nice with high g.
Lyle Ritz Solos (the blue one) uses high G. A lot of the melody notes are on the high g string.
It's my all time favorite jazz uke book. The arrangement of Quiet Nights of Quiet Stars is sublime.