BSA must have based that idea on their history of making precisely-engineered motorcycles (hahahahahahahahaha!) as my 1973 Meteor has numerous deviations from the concept of 'precision'. I see no-one is clamouring to buy the 'piled arms' badge to stick on a Shanghaicycle.
And Webley sent you a history? Well, they are now. Innit.
Tant pis.