I have a sheet music page for the Baez "John Riley" that has the notation:
"By Bob Gibson and Ricky Neff, © 1961, 1966 by Sanga Music Inc. and Harvard Music Inc. All rights reserved."

The Gibson/Neff credit appears on the Byrds album, The Notorious Byrd Brothers.

Bob Gibson introduced a then-unknown Joan Baez at the Newport Folk Festival of 1959.