As far as I know Drogo did NOT bodied this particular car, but the Jet Competizione and Jungla.
Motoring Journalist Wolfgang Blaube had the opportunity to interview Conte Volpi*. He tried to decipher the strange nomensclature of Serenissima models, but except of 'Jet', 'Torpedo' and 'Agena' there never were 'official' names for the cars. All in all there weren't more than eight (!) different one-offs built by Serenissima. All of them survived, but nothing is known where this Agena car is located (same with the Tjaarda designed Ghia car**) . Only Volpi himself got the key of some mysterious garage somewhere in Italy....
* for more info read German OldtimerMarkt 9/2008
**Volpi never accepted this car as being too heavy weight for a thoroughbred Serenissima sportscar.
EDIT: I was wrong about Drogo. He most probably built the bodies for both cars Strada and Agena!