Possible Clues:

• Return from major surgery that's not succeeded
• Commit to buying a home, if trade picks up?
• Swap over shillings or sixpences, say
• In a manner of speaking, Barney produced One Direction, Kiss and Cash
• Trade in obsolete coins?
• Brief argument in place where shares are traded?
• Discussion notes available here
• Former leader of clan almost strung up in market
• Act of giving and receiving
• Argument coming from retired coppers, perhaps