for now i will post just the tracked paths

here in the right place

seems youve fallen to the "flat art" sickness.
the chin area will need alot of reworking to make it look right on a sphere, got the width mostly right it seems, but you'll need to drag the chin outwards to map correctly

looks a bit rough atm, alot of the extra highlight/lowlight lines look rushed.

overall the sketch looks good, hopefull it comes through on the sphere

I wonder ir as well... the highlight look pretty fine.. maybe you dont see it but there is a big scar and lack of superficial skin on the right side which will extend to the missing ear, some teeth are exposed as well cause the missing part of lips.
not even 1 hr and i got kinda sick of it.
The hardest part, as with the Old Man Head is to do some proper hairs.. Whit this style of drawing and highlight and the fucked up mapping 80% of the tries ends in fails. wanted to post the update but my cs5 crashed when i was c/p the work from Illustrator to Photoshop. God dammit