It was indeed a Dealer Accessory, for 47-53 Chevrolet Medium Duty trucks. There was a smaller version available for the light duty trucks. I've owned three of them, just like this one. I sold the one I had on my 53 Chevy COE Wrecker, to someone on here, several years ago.
Studying the design of the one I found, I believe I have the one for 1/2 to 1 ton light duty trucks because of the distance from the top of the bumper to where this ones' headlight rings are located - hoping someone can find a photo of one actually on a truck
