Well found!
From Prewarcar, 2015:
"How many people can claim to drive a car built by one of their antecedents? Roy Halsall is one of this tiny minority of old-car enthusiasts, owning a rare Wilton 10/20 tourer that was built by the company founded by his grandfather, Charles Frederick Halsall, in 1914.
Charles started out making bicycles back in 1896, aged 14. By 1912 he was offering cycles powered by small engines, and that same year experimented with his first four-wheeled vehicle. It was a cyclecar powered by a JAP engine, very much in the spirit of the times, but when full production commenced in 1913 it had metamorphosed into a 'proper' light car, with a water-cooled 1095cc Ballot engine mounted behind a curved brass radiator. Charles's 'factory' was a tiny building behind his cycle shop in Wilton Road, Victoria, London, the location providing a name for the cars.
Production was slow, given the constraints of space and labour, and only a few Wiltons were built. It was thought that none survived until Roy Halsall located this car, the fourth made, in Australia. He has painstakingly restored the car over the last seven years and it is now in as-new condition."