Getting back to the original question and intent of this thread....

I think it is important to evaluate the very purpose of setting up his products on the store shelves. I believe the purpose is to sell and make money. Educating the public is secondary. Differentiating one's product is only meaningful if it promotes sales in this context.

Vast majority of people who will pick up the product will not even read, know the difference, or care how the product was made. Being eye catchy is far more important than being technically correct. Harping on technical details and superiority of silver gelatin prints mean nothing to the audience if they don't care - even if it's true.

If I were doing this, I'll make a red shiny sticker that says "Printed by Hand" or "Real Photograph" to spark some curiosity. Then include a small piece of paper explaining what it is.

Just because we, the photographers and the enthusiasts care, doesn't mean at all, the general public that will be the target of OP's venture, will care. I think (myself included) we care way too much about the technical details of what we do. General public wants pretty pictures and wants it for as little money as possible.

Because of nature of his setup, collectors and enthusiasts won't be his customers.