The fellow is correct, it is a California Masi, but not a Carlsbad. Carlsbad stopped production in late 1976, there were some NOS frames sold for a period thereafter, along with some contract built bikes. Albert Eisentraut even built some. Your bikes numbering scheme and placement indicates for sure After Carlsbad.

Very well could be from the Rancho Santa Fe period, when they were built in an outbuilding of an estate. This is prior to San Marcos. Rob Roberson works for Joe Bell bicycle refinishing in San Diego currently.

The Roberson built bikes are gaining a following, he is known to be very detailed in his work. So are the Dave Moulton built frames.