I thought I would share this here as it helps put the whole thing in perspective period wise...I'm thinking early to mid 50's... https://www.historic750formula.co.uk/austin-7-independent-suspension Quoted below... "Both of these kits were available in two track widths. 3ft 4inch standard Austin and a 3ft 9inch extra wide. Of course, most Specials in the 1950s took advantage of the wider track and also added offset wheels with yet wider and wider tyres in the belief that this was the way to go." ...If this is what Don used there is no doubt in my mind it was modded by him to suit his purpose and by that I mean he may have split the bones...adapted spindles...etc...