The only Boxer that I can find is Jack Gibson (Gateshead) was a professional boxer who was active between 1904 and 1912 He took part in 6 professional contests. But the ADRIC man claimed to be born in London
And although the register has that he deceased 26 Nov 1920, I cannot get that death in Irish GRO
1881 Mar 28 Born London
1920 Oct 8. Joined with RIC no 74084 & ADRIC no 92. ex-Soldier & Pugalist
1920 Nov 26 Deceased