Dating is an estimate from www.ausreprints.com.
"© S.I. Artists" This story is also printed in Grandes mitos del Oeste (Toutain Editor, 1987 series) #nn (1987).
Story drawn and printed in landscape (on side).
The spanish comic Jaimito (Valenciana, 1946 series) had a series called 'las aventuras de Juan Mestizo' in 1978/79 [at least issue 1563-1571], possibly earlier. Mestizo translates as "half blood" or "mongrel". This story ends with "Next Episode: 'In Santa Fe'". An internet sales listing at one point suggested that story could be from Jaimito #1571. Some other Australian episodes spell Mestizo's companion 'Arquimedes'.