This is what Neville has to say about this car. Not much, but still a first-hand info
"Hi Pawel, I believe I know what you are referring to. Early in 1967, having left Rob Walker's (and with the MiniSprint project sold by Geoff Thomas to Stewart & Arden) I was approached by David DaSouza and asked to design a sectioned mini hatchback. The prototype was built in a garage at Codford near Warminster owned by one 'Todd' Sweeney. From my recollection it was known as a'Codford conversion' I think two were built but I never saw a finished car, or even heard of it again until your email! with kind regards, Neville."