Peculiar (And Fake) WW2 London Auxiliary Ambulance Service (LAAS) Overalls

A most peculiar set of overalls that belonged to a volunteer with the London Auxiliary Ambulance Service (LAAS). I've not seen overalls in this design before and the bespoke badge is most interesting in the way that it can be removed fro the overalls.
UPDATE: It would appear that the original seller of this item has a somewhat notorious record of producing fake items. Thought the original boiler suit is vintage the badge and name (seems that have a proclivity for stamping white lettering on post-war boiler suits) have to be taken with a pinch of salt...