A number of old snippets and advertisements may throw a new light on cars believed to be 1960s coachbuilt Minis by Hooper and Radford in the UK or Taka-Hira in France. This as there were a number of companies offering wicker trim for application to these cars. From one article: "At the last Paris salon a Mini-Minor was shown with painted basket-woerk on the body and it set a fashion-pace in cars which is outmoding any romotion colour. This transfer method is widely used both in France and America."
I think the salon they mention must have been the 1961 Paris Motor Show, where Taka-Hira showed a cool Mini saloon, which was also featured prominently in Paris Match magazine. Two British companies which offered wicker in a number of colours and varieties called their products 'Wickertrim' and 'Shamkane' and there was also Humphrey Metcalfe in London who was happy to do the conversion and offered it in three colours, too.