Charcoal portrait

Hi Matt, 

I am working on this portrait in charcoal,  he was my first art teacher back when I was in Colombia South America and a good friend, we all are doing some artwork to commemorate him as he recently passed away.

This is the only decent reference picture of him that I could find and the quality is pretty bad. I’m having  a hard time seeing some shadow shapes as the pic is pretty blurry to make it look believable and get the likeness. 
Also not 100% sure about the design of the background and composition as I think I went a bit crazy experimenting with the textures.

thanks for your advice .

Camilo.