it may be that the name jimmy john is quite literal that is a"john"thatis a toilet where one had a"jimmy"- a urinal; urine, was a valuable feedstock for the chemical industry and publc provision was made for its collectionin the uk ,andmaybe in the u s
,one can only imagine the attraction these collection points must have for professional ladies,with a ready supply of customers ready to"dance"with them,especially whem the railway workers were in town