I guess the concentration on this is two things:
1. The facial features of the man at work when he is concentrating and the satisfaction of the job that is done. I don’t think though that he will take it home with him. The time on and the time off are of equal importance. So there are subtle differences even in the glances when he is speaking to the people he is working with and the people that he is serving. That is the most important trait to pull out here for me. I think the facial expressions are essential here. Now, how to put this on paper will be a different thing. Should the character be a butcher or fish cutter? Does it matter? I think something skilled with a knife in their wants, then transitioned to something skilled in their job will work well. Does he carve at home? Does his still use knifes at home? What is the difference? It would be interesting to see if it carried over at all.