Dave-
He was an enlisted man. I remember being surprised by that. I didn't know the US had ever had any enisted pilots.
Some other nations have; may still.
Some of the top Jap pilots in WW II were enlisted men, petty officers. The RAF and the Luftwaffe also had some enlisted (NCO) pilots.
The guess about the Western "shark" knife is right on, I think. If not, I'm pretty sure that it's a similar Western pattern that I saw being used by a fellow airman in the 1960's. That one had an eight -inch blade, but the "shark" model was shorter. Supposedly, Western felt that men at sea could use the knife to stab a shark if the ship sank or plane crashed. I'm sure they also saw it as a general purpose combat model.
Brubaker was a lawyer from Denver when not on Navy duty. Western Cutlery was in Boulder, so it's logical that he'd have bought a knife made in Colorado.
Movie prop men being what they are, that's probably a coincidence, though. I doubt the prop buyer had even read the book.
If CAG's knife isn't a Marble's like the Ideal, it may be the Remington RH-36 copy of that knife. After Remington quit making knives, Pal bought their patterns and made them for awhile.
Both knives look very authentic for US pilots in the 1950-52 time frame. I'm hoping that they also carried scout type pocketknives.
It's a pity that Navy aircrews then weren't given better handgun training. Even now, most pilots don't take their sidearms seriously enough.
On the off-chance that anyone cares which knife I'd carry as a pilot now, it's a close call between the Fallkniven S-1 and the Randall Model 5. I think both will fit the sheath on the survival vest. For less money, the Buck No. 119 Special is a good knife, too.
I've tried to see that knife a couple of times as I watched the DVD. I actually saw it better on YouTube!
T-Star