Well somebody else has said JOC always used and carried a regular trapper pocketknife to cut up his animals, but I don't know
Whoever said that was correct.
"The only knife a hunter needs is a good, strong, well-made pocket knife" - J.O'C, Hunting in the Rockies, 1947.
"For a hunting knife the sportsman should choose a good substantial pocket knife" - J.O'C, Hunting in the Southwest, 1945.
O'Connor wasn't a fan of belt knives and said so rather caustically in both books. If he mentioned anything about hunting knives in writing after those two early books I've never seen it.