… But their main business is in parts and refurbishing, and the old man, Deforges, doesn’t like to sell a used piano to someone who hasn’t come recommended. He says it’s more trouble than it’s worth and he’s got plenty of customers for the pianos that come his way. (The Piano Shop on the Left Bank by Thad Carhart)
I think the rough meanings would be the same if the sentence used “who hasn’t been recommended” instead of “who hasn’t come recommended,” but what’s the difference between them?