Re Jowett vans, as a child in Cornwall, I used to be fascinated by what I recall (possibly faulty) as a Jowett van delivering Brooke Bond tea to the village shop The fascination was the engine noise, a distinctive 'pop-pop', reminiscent of a muted version of the Field Marshall single pot tractors.
Memory, which serves me badly nowadays, tells me that the engine was unusual in being 'opposed piston/cylinder'. Anyone confirm or clarify, please?