This is a California Masi, but not a Carlsbad example. Carlsbad was done making bikes in late 1976. This bike has the short dropouts and the fork crown indicates what used at San Marcos for a time. The frame number is also post Carlsbad. The lower head lug looks different from others in the period, the cut out is narrower and wider at the extremes. Also this frame is very different as there are no down tube water bottle braze ons, yet it has shifter bosses brazed on...Chrome is probably a later modification.