You could check to see if one of his games has that position using https://fenfinder.com https://fenfinder.com (site I built). Of course it's a long shot given

You could check to see if one of his games has that position using https://fenfinder.com https://fenfinder.com (site I built). Of course it's a long shot given the huge possibility-space of unique positions, but hey, one can hope :).