This is a CEV rear light for a Ducati Bevel 750 GT Sport and SS  Could also fit oder Italian models.  Nice state, but the body is not completely round, see pictures.  

Ducati roundcase, Imola, Greenframe, SS, SD, GTS, MHR, SSD, Darmah, squarecase, S2, sport, supersport, Borrani, Ceriani, Scarab, Lockheed, Marzocchi, Brembo, monza , diana, mach, mach1, dm250, dm350, dm160, 160, 450, dm450, desmo, desmodromica, elite, elite 200, brembo, 900SD, Mark 3 , mark 2, CEV, 750, 750GT, 860GT, 900GT, MV Agusta 750 America GT SS