SOooo' I can muck around for hours trying to "find" him (and hone my drawing/painting skills, yes) OR I can do what a purist would call "cheating" and I call a means to an end. I suspect this is done more than most painters will admit but I will share it with you rather than pretend I'm an ace at portraiture.
Here's what I did: I measured the head in the painting (6 1/2"). Then I opened the reference image in my computer and cropped the photo down to just the head- crown to chin. Then I printed the image choosing the size of 61/2". Now I have a photo I can lay over the painting and see where I have gone astray. Watch the video:
Ah HA! the reason he looks older is because I've made his features too small! And, I've made my classic mistake once again of making the right eye too low. That's why the angle of the head looked off.
Now this looks more like the photo - with plenty of room for my interpretation or "style".
It's interesting that I can see bits of his sister that I had not noticed before. I'll let this dry before I do any more, so if I muck it up I can at least go back to this and try again.
And in the meantime there's a very interesting fretting hand to work on.
Stay tuned - there will be more. Did you like the addition of video in this post?