I've been looking through old digital copies of Boys Life magazines, the official magazine of the Boy Scouts, reading the old articles and ads. There is a wealth of information in those old publications.
One of the things I am doing as I work my up from March, 1911, the first issue of publication, is recording the appearance of knife ads and copying the knife/axe/hatchet/tools ads.
The first knife ad appears in the third issue, April 1911. (March 1911 had 2 issues.)
The ad was for a 2 blade knife with watch fob chain by the New York Knife Company.
Here's the ad - from the text, you can see that the advertiser, Perry & Co., was actually trying to entice young scouts to sell their product "Sylvan Bouquet" sachets, and remit the money back to Perry & Co,, in exchange for having the knife sent to them.
I'll eventually post up a separate thread in Traditionals of the knives of Boys Life.