Glad the article arrived. I looked at "A Bibliography of Archery" and saw a number of articles cited that had been written by Earl B. Powell. In tracking down the article you requested, I noted one article written by Powell that wasn't listed that appeared in the October, 1931 issue of the "Archery Review" entitled "How to Shoot with the Longbow". You may have this article already as part of your Powell research/data. If not, let me know.
I also saw an advertisement in the November, 1931 issue where he was soliciting financial backing for "A Bow and Arrow Hunting Picture".
The picture/film was to feature hunting Jaguars, Ocelots, Tapirs, Deer, Turkeys, Alligators, etc. in Mexico and Central America. Apparently, he thought that it would only cost between $2,500 and $3,000 to produce the picture. He had previously produced a picture showing the hunting of alligators.