Chris has posted a picture of his Dad digging the foundations for the Swansea Uplands Rugby Football Club at about the same time. (This also contains a link to a history of the club contains the strangely inspirational fact that "the club played its final pre war fixture on tour against Old Whitgiftians in Croydon on 10th April 1939 and following a meeting held on 18th April 1939, the club enlisted en-bloc forming a “sportsman’s platoon” in 5th Battalion The Welsh Regiment".)
I've also found two posts on Paul Flynn MP's website that show details of a photograph of the staff and pupils of St Illtyd's in 1947. I can see my Mum's brother Michael Milton on it and I am sure it should feature my father as well but I can't seem to find him.
(The links are: http://www.paulflynnmp.co.uk/hotnewsdetail.jsp?id=496 and http://www.paulflynnmp.co.uk/hotnewsdetail.jsp?id=506).
Finally, another photo of the Old Illtydian's off duty in the 1950s toasting a stuffed wolf. Go figure.