This could be Donald Edward or Edwin Dennison, born 1924. He was born in London and his last known address was Pirbright in Surrey. There is no apparent connection with Penarth.
Donald served in the Merchant Navy as Mess Room Boy aboard S.S. Chulmleigh (London). He died on 26th November 1942 and is buried in Tromso Cemetery Nn. A. 4.