This list is highly active with (in my case) many fascinating replies coming off list and private. I will say that I am now fully convinced from details and photos that I have received, that my Gios Professional is authentic. It seems that many Italian bikes that were indeed made in Italy came without serial numbers so that the bikes could be sold without having to pay taxes. This almost adds to the mystique of an Italian machine, with the further romance of bikes being sold from famous marks in something that resembles an underground market. In the particular case of Gios, it also seems from information that I gleaned from Sheldon Brown's site, that there were counterfeit Gios bikes made in Mexico. It further states that some believe the counterfeits to be superior to the Italian Gios machine. In what ways would the counterfeit be superior? What would a counterfeit look like? I have seen other bikes, such as a Windsor, a Bennotto and a Merckx that the owners claimed were made in Mexico. Nothing about these bikes seemed superior to what I have seen coming from Italy. I am sure that there are fine craftsmen in Mexico as there are anywhere in the world, but my understanding is that bikes that come from Italy have a cache that adds to their value, and also that Italy had more than its share of the finest builders in the world.