Apparently you never met them Fats was very friendly and entertaining to talk to and happy to give an autograph Mosconi was an ass and didn't want anything at all to do with the fans and would try and not do autographs.
Not true.
Over the years I lived in SF I saw Mosconi put on an exhibition perhaps four times. When he was playing you could see the hate and contempt Mosconi had for all his opponents. It was said that in championship play he hated to lose so much that, while he was in the chair, he'd chew his tongue until it bled.
But at his exhibitions he was quite cordial afterwards and would sign anything and talk to the fans at length. In fact, one of the reasons Mosconi's autograph is not worth as much as that of some other players is that he toured the country over and over and would sign just about anything handed to him: paper, posters, books, CBs, and cues. There are thousands of Mosconi autographs out there. Even I have one.
Lou Figueroa