And the real David Grayson is...
The man on the right is the real David Grayson. There were imposters around the country, and because many did not know what Baker looked like these men often did not bear any resemblence.
Before the reveal of Grayson's identity, when a man came into town saying that he was the famed author townspeople would write to the editor to confirm the identity. The editor would then say that whover this person was, was a con-man. Baker never went anywhere int he country calling himself Grayson so it was never him.
After the reveal of Grayson's identity people would write directly to Baker. The other two photographs were sent along with these letters. Baker or an editor would reply telling them that it was an imposter and that they should contact the police and not give the man any money or shelter.