How could I approach a maker of snuff boxes and ask about getting an old timey looking picture applied to the box? Or would it be easier to buy a snuff box and do it myself?

You have to contact with some graphic-media studio, send them a picture and order. Then you have to put this on. for example, wooden box. http://www.margraf.pl/

You can buy blank decal sheets and print your own designs and then apply them easily

Local engraver maybe for a metal box

Try doing it, There is the satisfaction of creation. Now I could never paint a picture on the inside of a snuff bottle. That stuff just blows my mind.