Small man's portrait painting

Any clues on the nationality of the depicted man?

 

Removing the old yellow varnish he looks European.

 

It is after what was thought to be a Rembrand painting but turned that most likely was done by a follower of him.
http://www.nationalgallery.org.uk/paintings/follower-of-rembrandt-an-old-man-in-an-armchair

To me it looks like in this example the face was rendered to look more Eastern European, maybe Russian?