Update 11/20 Not Desmo, but we have a very nice replica of the Lucas King of the Road horn available for sale now! Check the homepage for photos and details.
Reader Iguana, shared a video that opened up a whole new window on the world of Squeezehorns, Taxi Horns, Bulb Horns and… the one and only Desmo horn! Amazing!
They spell it many different ways.
Desmo, Deshmo, Deshmuk, Deshmukh.. Sometimes bhopu.. Maybe that will help you ask for the right things.