The Firearm Blog has photos of works done by Iraqi engraver Noori Sabeh. Engraving gun is centuries-old practice that can be done with a wide array of tools. While moden facilities use CNC machines, this man has to work with simple tools.
http://www.thefirearmblog.com/blog/2016/11/17/iraqi-firearms-engraver-noori-sabeh/
From: The Firearm Blog