Voltage regulator cross-references - Bosch electronic
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
Updated:
Originally, Moto Guzzi fit a mechanical Bosch voltage regulator. While not original, the Bosch electronic voltage regulator is an excellent choice when a replacement is needed.
Thanks to Dave Washburn and Charlie Mullendore of Antietam Classic Cycle for providing this information on the old Yahoo! Loopframe_Guzzi news group (which has now moved to Groups.io). In Charlie's own words:
...bike also needed a voltage regulator and I've had less than stellar results with the usual AutoZone/Advance Auto Parts supplied units for Bosch generators. Had two fail within the first month of use. This time I decided to use the same Bosch electronic voltage regulator: (Part Number 111903803D) I installed on my 72 Ambo
Sophia. It's been on there for three years with zero problems, begins full output at a lower RPM than the mechanical units and actually costs about the same.
This voltage regulator is available from MG Cycle.

Photo courtesy of Wolfsburg West.

Photo courtesy of Andy (glutamodo) on TheSamba.com VW forum.

Photo courtesy of Bosch.