It seems there is no end to discoveries. This was quite a find for the former Disney animator who is working on a painstaking animated reproduction of the Gettysburg Address. The Lincoln-spotting has yet to be authenticated, but given the tremendous effort Christopher Oakley has put into this project, you have to figure he knows Lincoln when he sees him.
When trying to create a three-dimensional image every photograph counts. I've discovered this in trying to reconstruct historic buildings from photographs, often having to work with poor resolution photos so that you have to rely on classical proportion systems to make up the differences. But, with a human face it must be exceedingly difficult.