Unknown charcoal on paper from grandma's art collection

http://imgur.com/gallery/k5n7R

Found this piece tucked away in my grandmother's art collection. It is a very well-executed charcoal on paper. She lived in NYC through the 1940s, 50s, 60s, etc, and had access to some very good art. Can anyone help me ID this? Image searches on the signature have not yielded any results. Thanks!