I agree, he's a Red SL roo. They are a hybrid specifically created for high production capacity egglaying hens. Hatcheries have no use for the males created by the process, and probably put it in with the meaties as a free 'stewpot' bird.
You can show him at a county fair, just not as a specific breed since he is a hybrid.
He looks really docile, good on you for giving him a happy life.