In the Erdnase thread, I made note
of an early use of the phrase "mechanic's grip". The article from which it came also mentioned the trope about gamblers amputating their finger to the first joint so that they don't flash as they push out a bottom card. As I read that, it struck me that this was the first occasion I knew of the story (A fabrication? Urban legend? Possibly true?) being in print. Turns out, it predates the Life
article. Google books has a link to a 1923 article or story in Sunset
featuring the elective surgery:
Wilbur Hall. "Cheating Chance" Sunset Magazine
, Feb 1923 p 17
"When I expressed my admiration Quirk dealt a round slowly and disclosed to us the fact that the absence of those two joints on the second finger enabled him to draw the bottom card with absolute neatness and smoothness, and then he confessed that, finding the finger interfering with perfect work, he had gone to a surgeon deliberately and had it amputated."
More research will, no doubt, push this even farther back.