This is a nice rendition of a really hard to paint bust. I have this myself and found there to be too many wrinkles in the face and neck for my liking. I filled these in with milliput to smooth the skin out a bit. I also used photos of the actor James Gammon who this really resembles. The eyes are a nightmare to paint and on your version is the only part I can criticize. With mine I again filled the eyes so they were smooth and painted them looking to his left rather than straight on. It seems to humanize the bust a bit doing this. Just a few tips. I must get around to putting my version on here.
John
John