The body on K3004 in the 1957 photo is an "Ausca" body which were made in Melbourne by Paul England to the form of a Maserati A6 GCS. Jim Gullan was the owner of K3004 at the time and as the K3 was was being out classed by more modern machinery in the racing car divisions he re-bodied it for sports car racing. In this form it won its class in the 1957 Victorian TT at Albert Park (when the track ran the opposite direction as they raced the Aust. GP last weekend). There were a dozen or so Ausca bodies made:
Yes Cat, you are right. "Porthos", one of the 1935 Musketeer Magnettes was fitted with a fibreglass "Mistral" body in the early fifties when it was owned and raced by Chris Lawrence. Lawrence later became well known as the proprietor of "Lawrencetune" specialising in very hot Morgans.
Getting back to Mrs Corbett-Fisher, I have never been able to establish whether she was related to Stuart Wilton or perhaps she was just a very nice lady who had lots of money. She first started to enter events in September 1937 with QA0254 (the Evans family single seat Q Type) for Stuart to drive. By April 1938 her attention turned towards K3004, again with Stuart doing the driving, which he did very successfully until August 1939. In his hands the K3 went extremely well, and at the VSCC Lewes Speed Trials held on the 15th July 1939 he made FTD with a time of 21.60 seconds.
With further searching on Mrs C Corbett-Fisher I found that her daughter's name was Bridget which ties in to the Entrant for the Ford Motor Co Gymkhana at Brooklands on 17/6/39 listed as a Miss Bridget Corbett-Fisher. Bridget moved to Australia in 1946. I have been trying to contact Bridget Gilling relations in Australia to see if they have any family knowledge that Cicely Corbett Fisher did own K3004 which I think was highly likely.