Scottie - Sorry, but busts are always fast for me - usually three days max.
Neil - I used the box art for colour reference, which has an all white sheepskin with a detachable brown collar. However looking at photos it seems I could have done the the main colour in buff, which would have been easier.
Fernando - The secret with white is to build it up with ever lighter coats of grey, as adding a bit of darker pigment to the white thickens it considerably. Glad you like him.