I have a friend who has a laser engraver. I recently gave her a .GIF of my mark and had her burn it into the end of a 3/16" punch (in reverse of course).
I have yet to try it on something ferrous but it makes a lovely mark on copper and silver.
I'm trying to gauge what interest there might be in custom punches.
What would it be worth to you to be able to punch your own graphic into your work? What size would you want it to be?