Re: the three RCAF members lost.
Donald Fullerton Neilson was the only child of Neil Hingle and Ellen Maud (née Edwards) Neilson of Buenos Aires, Argentina. Neilson Senior, originally from Liverpool, was a cattle rancher with properties in Argentina and Canada. Neilson was working on one of father's ranches in Alberta when he enlisted in 1942.
Harold Beverly Brett had a brother and two sisters. You can find his sister, Lillian's, family by following this link: http://www.genealogy.com/ftm/m/i/l/J.../UHP-0131.html
John Kay Murray, although listed as coming from Ontario, enlisted in Winnipeg. He had two brothers, Charles and Robert, both serving overseas and one sister, Marion. His father, Charles, had died 6 February, 1936 and is buried in Swan River, Manitoba.