Hamish Henderson's "John Maclean March" predates Hanley's "Scotland the Brave" by a couple of years - the tune is very slightly different. The tune appears as "Brave Scotland" in the Gesto Collection of the 1880s, but I don't know any words to it before the 1940s.

Do we have a chronology for "O'Donnell Abu"? I don't know it.