Possible Clues:

• Cockney who's decorated a line in old capital
• Flamboyantly-dressed trader in city once stocking top-quality line?
• Fancy London trader wants a railway through the city
• The sort of Cockney who rules on poor player?
• Regal costermonger
• Distinguished Londoner's parental guidance, guarding young family
• Londoner geared up, as things are coming to a head about railway