Good to see you back on the 3D wagon C! John's drawings are great, very simple but they have susch a cool style. It's gonna be difficult to get that look right, but the 3D guy is starting to look good.
I'd say get those eyes bigger, and the mouth too... exaggerate everything!
You've only got a sphere to work from so it's gonna be tough - but I'd say if you can get some heavy, expressive eyebrows in there, it'd be a 80% of the work.