I do similar to Steve, but I use the tiniest bit of Prussian blue added to the base flesh color, for 5 o'clock shadow, just the point of a 00 brush dipped into the blue, a smidge, an idea, a hint, of the color.
That's looking good mate
My mix is Paynes Grey with a wee bit of Prussian Blue.
Nice soft brush with virtually no colour on it carefully dabbed in place.
Remember where it covers bone like the jaw line you can try a light overlay with PG mixed with a little Tit White.
Looks like you've acheived this
Cheers
Derek