He said one way to tell if his father truly signed or not is that he always signed his name "Peter Y.Y. Choo, Jr."
Better tell Uncle Frank his certificate is a forgery.
He said he met you in Benicia in 1997, when he and his brother went up for some kind of tournament and celebration, after his father passed away.
I've never heard of or been to anywhere named "Benicia". And I'm sure if I had met one of the founders sons, I would remember it. Only one's I've met are Vinson Holck, Alvin Emperado, and Clarence Emperado Luna.