John Windelburn sent me this in what he believes is Dennis Marwood first event in the MG TD.
The Waikato Motor Racing Club event a North Island Championship Hill Climb ... held on the 17th March 1956.
John was there in his Morris Minor which he had prior to the Austin A35 and many others cars since.

Name: John Windelburn #058 Waikato MRC Hclimb 17 Mar 1956 Dennis Marwood MG TD J Windelburn De Soto 17.jpg Views: 87 Size: 178.2 KB

The previously posted photo of Dennis at Waharoa in the MG TD is also believed to be from 1956