Good Painter Propaganda Poster

This is an illustration I made for my TA. He is a very accomplished painter, so I thought this would be a good depiction of him. It goes along with the first portrait that I did in the WW2 propaganda poster style. I really like how it turned out, but it was very challenging when using only Illustrator. The biggest challenge for me was how to show the facial hair and getting the correct skin tones all while keeping the same feel of the reference poster below. Any comments/criticism is much appreciated!