Sirens supplied by Moto Guzzi
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
Starting with the second edition of the V700 spare parts catalog, Moto Guzzi supplied a pair of electric sirens (MG# 12743740 and a pair of mounting brackets (MG# 12744240 and MG# 12744245). To the best of my knowledge, these sirens were manufactured by
Ercole Marelli SPU and are designated as part number 120.
Ercole Marelli was one of the founders of
Magneti Marelli (along with Fiat). Given that
Magneti Marelli was founded in , I'm confused by why the spare parts catalog identifies the manufacturer as
Ercole Marelli rather than
Regardless, these sirens are very rare and I've never seen any in person. The closest I've gotten to these is the photo on page 26 of Greg Field's most excellent book,
Moto Guzzi Big Twins.
Friction drive sirens
Moto Guzzi made frames with rear-tire-friction-drive siren mounts for use by police departments. Moto Guzzi did not, however, manufacturer or supply friction drive sirens. Instead, individual police departments mounted a variety of sirens as per their department preferences. Some departments used electric sirens while others used mechanical sirens.