The little bald head with the long nose peered over the wall and the slogan below always started: 'Wot no ....'. I was told the rest always referred to wartime shortages, as in: 'Wot no bananas!' But I was only born in 1942 but clearly remember loads of Chads still being around so it must have carried on for a few years after the war ended. Watneys later featured him in poster advertising - 'Wot no Watneys!'
Incidentally - and miles off topic, for which apologies - I can remember my mother bringing home a fresh banana for the first time, presumably after the war ended, and being amazed that they came as curved individuals in a yellow skin and were white inside as opposed to being brown and sticky, cylindrical and several stuck together, which is what I knew as bananas on the rare occasions I'd seen even those!