From the Montreal Gazette, 19 July 1944:
Wounded List
Royal Canadian Artillery, Central Ontario Regiment
Cooper, Herbert James, Rfn, B-138893, Mrs. Martha A. Bushell, mother, Rochester, Kent, England
This service number matches up with what you posted elsewhere and does not jive with letters received from his mother thanking your family for looking after him while he was in England so unlikely he was born in the UK.