As a side-effect of some research I found some new information in NY Times.
NEW YORK TIMES
6 FEB 1919
"Irving Margolies, the former amateur bantamweight boxing champion, who recently entered the featherweight ranks in the professional game, died yesterday of Influenza. Margolies contracted the illness shortly after winning his bout with Freddie Reese, a semi-final to the Benny Leonard-Johnny Dundee fight at Newark on Jan 20. It was the first time Reese had been knocked out in his career".
NEW YORK TIMES
26 JUN 1922
"Gunner" Arnold (ID 123059) died in a Harlem hospital on 22 June. He died of Pneumonia and a haemorrage to the brain.
NEW YORK TIMES
28 DEC 1897
"Cleveland -Dec 27
John Donaldson, a well-known sporting man and prizefighter died here to-night.
Donaldson was considered a clever pugilist fifteen years ago. In 1880 he met John L. Sullivan and was beaten in ten rounds."