Possible Clues:

• Head warmers
• Occupiers of top spots
• Beavers, perhaps
• Milliners' output
• After a century one talks about them being on top
• Roles, idiomatically
• "Billy Two ___" (1973 Gregory Peck film)
• Berets and fedoras
• Ring-tossed items?
• Cowgirls' accessories