First of all, I have one of those old Vespas, a 1978 P200E. Absolutely love the thing. I also love the concept of no pedaling. I am not lazy, I am disabled, and cannot pedal. I only need the pedals for legal reasons. Yes, I can (and do) ride a scooter and a small motorcycle, but as a former cyclist, I love the idea of riding a bicycle. Just no pedaling.
How does your setup attach to the bike? Does it use any of the cheap crappy parts like the Chinese engine kits do, like the rag joint rear sprocket and flimsy (and dangerous) idler pulley? If it is a quality setup, and if you decide to export to the U.S., I might very well be interested.