According to boxrec he lost to a man named soley "Mayo" Mr Mayo's win over the hall of famer is his only recorded fight on boxrec. Do we have anything else on Mayo? Maybe a real first name and last name?
Probably William Mayo, who was reportedly heavyweight champion of the Northwest around this time. https://boxrec.com/en/box-pro/267339 The report of the Smith-Mayo fight gives Smith's weight as 168lbs which, if true, means he was either grossly overweight or, more likely, not actually Billy Smith the welterweight champion. https://ibb.co/H49fgbb
Everything about Billy was mysterious, including his opponents. Mayo’s last name is Clinic. He gave up boxing and went into the field of medicine.
Wow thank you so much. I didn't expect such a detailed answer. It would be weird for a welterweight to fight a heavyweight but it wouldn't be out of the question for that time period.