I am going to guess around 1980. I say 1980 only because I vaguely remember seeing the engine exhibited with that livery at a regional fair in Guatemala City, and 1980 would be the approximate time frame. Again, going on memory the 34 had been the switcher at Tecun Uman until a combination of deteriorating traffic and diesels made it surplus in the early 1970's/
JBWX