I do not think master swordsmiths would resort to such a rudimental process. If they could put a gold motto and trademark on a Damascus blade I am sure a signature would be no problem. Also there is noway someone is going to hold a hand held rotary tool ridgid enough to cut steel with anykind of precision,maybe a pantograph system could be used but why? and are there any other TR blades with such a process?

"Those who do not remember the past are condemned to relive it" Santayana