Date of birth was provided by son Theo; BMD death index shows 14 April 1931.
findmypast.co.uk has a Passenger List for the 'Warwick Castle', leaving London for South & West Africa on 6 February 1957 with B M J Minter on board. His birth date was shown as 14 April 1931, address 239 Felsham Road, Putney SW 15, occupation Traffic Clerk. He was bound for South Africa.