Hey guys,
Thanks for all the help and input! The pieces of the puzzle are indeed coming together. I'm quite familiar with the San Joaquin and Sacramento valleys. In fact, the San Joaquin monnicker is what attracted me to the gun. I grew up in Santa Clara (aka Silicon) valley in the 50's and early 60's. I'm in Norcal now but still hunt in the Central valley on ocassion.
Dunham/Carrigan/Hayden was in business in San Francisco from 1875 to 1946, sold eveything from "axes to yardsticks". Company records for all years are archived at the Bancroft Library at UC Berkeley and are researchable. So, with a bit more research, might be able to track down the original purchaser. Could have been sold individualy or possibly as a lot to a club.
Again, thanks to all for the help and information.
Craig