This carburetor is actually catalogued for Lancia Aprilia. There are others for sale as well. I know of one in Italy that was with a professional vendor and one in the USA with a private owner. Anybody who is interested may contact me via this forum and I will put you in touch directly.
I have a 36mm Memini that seems to be a functional equivalent but I do not know much about it. I picked it up many years ago at an Italian swap meet for a friend who was "collecting Memini carburetors" but his interests had "moved on" by the time I got it here. It will be substantially less than Euro 800! It will be a while before I can visit it to get additional details and maybe take a photo or two.