I've been involved in the construction of a couple of "fake" Cameos when my business partner in the body shop we co-owned installed the fiberglass fleetside panels onto a regular pickup bed. To the best of my knowledge, the frame is the same from 55-57 at least, regardless of whether it's a Cameo or not. However, it's been 40-something years since then and my memory could be a little faulty.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!