A Harry Loseby, age 35, buried Camberwell, 1920https://www.findagrave.com/memorial/218236925/harry-losebyCould be Harry N A Loseby, died Chelsea, 1920, born 1885https://www.familysearch.org/ark:/61903/1:1:2JHJ-24J?lang=enHarry Newton Arden Loseby, born Newmarket, S quarter, 1885, MMN Arden
No records that I can find of the mysterious Mr Loseby marrying Mary/Elizabeth Higgins in Ireland or anywhere in UK.