#57 Bob Bottwell, Triumph dealer from Baltimore, #16D Roland (Seed) Hedgcock. The guy to the right of the 58A rider is Sherman Cooper a dealer from Penna.
Early Fifties Daytona GP500, rider unknown but the guy standing is Triumph Service Manager Rod Coates
Gene Smith from Fort Worth Texas riding a Jack Wilson tuned bike out of Pete Dalio's Triumph shop. It is a flat track race rather than a TT, the front brake plate is removed and they are just running the wheel. Thanks to Keith Martin for clearing it up.
Unknown rider but a great shot.
Thanks to Sweet Pete D for the pics,
and Carl Williamson for the names to the faces.