Billings as "Jerry Garcia and Merl Saunders", but consecutive weeks' advertisements from Fred Herrera's clippings (the Fred Files) show a change, with California extended to Feb. 6 and 7 and Butch Whacks listed as tentative for Feb. 8 in the calendar starting with 2/1/75.
ad: San Francisco Sunday Examiner and Chronicle Datebook, January 26, 1975, p. 20
listing: Hayward Daily Review, January 31, 1975, p. 44
ref: Keystone calendar 19750125-19750210;
listing: Fred Herrera clippings;
ref: [contra] Keystone calendar 19750201-19750309
ad: [contra] San Francisco Sunday Examiner and Chronicle Datebook, February 2, 1975, p. 27