I do not believe that this frame dates from 1973.
Perhaps 1977 or '78.
I am not saying that there is an attempt to deceive, I just believe that the seller is mistaken.
Francisco worked for Denco, out of 14th Street Bicycles in 1973 through about 1977. I know because I worked there with him in 1974 and 1975. The frame I have that was built by him in 1975 is radically different than this one. To my knowledge, he had no decals at all at this time, but instead he used a metal diamond shaped stamp that he put on the seatstay caps. My frame has this stamp.
I watched Francisco use his "eyeball" method of building. He was pretty darn good. He may have done some cold setting toward completion, my memory is a bit hazy on this. I have heard the stories about frames breaking, but I can say for sure that I never saw one. My frame saw many thousands of miles. I was never the strength of rider that could tear frames apart. But I rode my frame across the US with 50 pounds of equipment hanging from it, crashed it on more than one occasion, and never had a moment's problem with it.
Not denying anyone else's stories. Just first hand experience.
More on my experience here:
http://cinelli.typepad.com/
Greg Pitman
Yucaipa, California
USA