A Villiers 1320 carb was also one of the carbs specified for the Jap 5 engine. I have yet to find more detail on this carb , but in my research , i have found a very interesting history of the Villiers company. They were a very innovative engineering company and created a broad range of products.
Vintage Pedestrian Tractors
Hopefully a helpful resource to all Vintage Pedestrian tractor enthusiasts