looking for boys novel

[jessiejack]

Im looking for a boys novel, that I read around 1965, based in an English boarding school where the boys played football and solved crimes. I believed that one of the characters was called Dinghy or Dingey. About 4/5 boys were involved. I can remember it was a hardback edition with a yellow dustjacket. Very limited information I know but any help would be appreciated.

Thanks in anticipation.