Stephan, the leather looks really nice -maybe i would only give it a coat of semi gloss varnish. On face I would work little longer -at this stage it seems to need at least few coats of glaze , and since it is a character from underworld (as in Undead?) , my main tone would be purple mixed with shades of grey, little burnt sienna perhaps .Glaze coatings would give more depth .
Cheers,Peter