Portrait by unknown artist

Picked this up today. It's an original and think it might be gouache. Sadly I cant find a signature on it. I have a feeling there was a label with more information on the back. You can see the outline of where it was. I have removed the mount which is stuck on with sticky stuff. Blurgh! The paper that it is on is also stuck onto the backing card with glue about an inch wide around the edge. Not much chance of removing this to look for clues on the back, without destruction. The artist has captured the facial features really well.