To return to the thread, the most distinctive, wide handlebars I've come across where those used by the Aussie World finalist Peter Moore, who came to the UK in 1952 at Long Eaton, and ended his UK career @ Rye House, I think, in the seventies.
He was at his peak riding for Wimbledon in the 50's, and Ipswich in the 60's , latterly for Kings Lynne in 1966.
Interestingly he was reckoned to be one of the fastest gaters of his time, despite the extravagant cow-horns.