Jeff,
Is the collection you mentioned The Lost Classics of Jack O'Connor? Unfortunately, a couple of the older stories in there were NOT written by the Jack O'Connor many of us grew up reading, but another guy with the same name. The one I remember for sure is about hunting Dall sheep in Alaska--and the "real" Jack O'Connor never hunted sheep in Alaska. It's pretty easy to tell the style is different as well.
It is titled "Classic O'Connor, 45 World Wide Hunting Adventures". Edited by Jim Cassady (sp?) ISBN: 9781935342090.
It has illustrations of JOC on both the front and back covers, so it looks "real".
It doesn't appear to be the same as the Lost Classics book, but it was published by the same people, Skyhorse Publishing.
I assume that it is just a compilation of stories that JOC published in OL magazine.
