We all know about Jackie Gaughan, but what ever happened to Mel and Larry? Larry must have joined the partnership later.

Jackie Gaughan's bookmaking talent led to the operation of such “joints” (as he liked to call his operations) as the Saratoga and the Derby, both downtown sports books. In 1961, he opened the Las Vegas Club with Mel Exber and Larry Hazlewood.

From downtownzen site at
http://www.dtzen.com/#!jackie-gaughan-bio/cr7h