Very little information is available on this unique Mosrite resonator model. These were made in the early 1960's and were available in black or sunburst. As very few are seen these days it would be a good assumption that production levels were low and it was not a successful model for Semie Moseley.
The Californian featured a double cutaway Gibson 335 style body with a resonator cone, two single coil pickups, master volume and tone controls with a 3 way selector switch. Bound body and neck, rosewood fretboard and a zero fret with a trapeze tail.
Early in the history of Eastwood Guitars, around 2003, they came out with a tribute to the Californian called the Eastwood Delta 6. For a more versatile design a few changes were incorporated. Instead of 2 pickups (one of which did not take advantage of the resonator) Eastwood offered a P-90 single coil in the neck and a Piezo in the bridge to help capture the tone of the resonator cone.
As the output for these two pickups are not the same level, instead of a 3-way switch they incorporated a blend control, to allow the user to dial in as much or as little as they wanted of each pickup.
Here is a demo of the Eastwood Delta 6 by RJ Ronquillo:
Another demo from Lance Keltner: