Would Texas Star care to attempt to identify the air crew man's knife in THE PILGRIM's picture in reply #33? They look like WW II navy airmen. I do not see the lanyard hole that onomea's Western in the original post has. I can not see whether or not it has Western's dual tang. As far as I know the pommel could be Western, Case, Marbles, Ka-Bar or a lessor known brand. Due to the incredible expansion of their fleet the navy famously scrounged all reasonable substitutes for their Mark I deck knife.
You described the situation well, and individual sailors and aviators also frequently bought their own.
I THINK the man on the left has a Western, but don't know the line well enough to know the model. The man on the right seems to have a different pommel, which I can't see well enough to be sure about.
Most Western pommels weren't drilled for a thong, so if one is, that may help ID the knife. I THINK all variants of their Shark Knife had drilled pommels, but am not an expert. Curved blades are not the Shark Knife.
Even when a make can be identified, as with Maj. Richard Bong's Randall, it's hard to know the knife in the sheath. Randall offered, for instance, "commando" shaped handles on both Models 1 and 2.
I haven't seen the Bong photo in awhile. If someone will post it, I'll make a guess, or maybe Gary Randall knows.
There's also a good photo of Errol Flynn wearing his Randall knife in the cockpit of his yacht. The sheath is just curved enough to make the knife ID hard.
The official Randall scrimshaw artist (Rick Bowles) is a member here and has access to those photos. Maybe he'll post them again?
In viewing British commandos' knives, look for the curved guard to see if it's a First Model, and the handle is silver. Third Models have ringed handles, not checkered.