All About Pocket Knives

I am calling this an L58, as I am not 100% sure what model / pattern it is.
But some do call it an L58. 5 1/4 - 5 3/8" , 3/4" tall blade with a double guard.
I purchased one, then got interested and found 4 more. Some are still in the mail.
Checked Platt's book, Coles book, and just a small blurb with 2 photos in Bill Walters book.
But nothing addressing this knife.
I did find some "guess" type explanations on the knife in old forum posts..
One being it was summitted to the military early on, It was deemed too small so they came up with the 6" Shark.
No idea if that is accurate. But sounds reasonable.

Have found both steel guard with thick WW2 style red center spacer, and brass guard with thin center spacer.
The brass guard version having a bit fatter leather handle. Am guessing it came later / just a guess.
Anyway, just wanted to ask if anyone here has info on this knife.
As I have tried, but have not come up with too much on it.
Thanks in advance!

(Last photo/ 6" shark for size)

I just found this, so it helps a bit. 1940's Field and Stream add.

MCM wrote: ↑Sat May 10, 2025 6:37 pm I just found this, so it helps a bit. 1940's Field and Stream add.

Western added U.S.A. On the third line on the tang stamping after the Pat . date some time mid 1947 or a bit earlier .USA . Remained on the tang stamp until 1953/1954 ish .just a guess the “new stye “ reference in the field and stream add may be the change to the full guard on your knifes that was a change from the half guard shown on the L 58 from the 1941 catalog pages and 1/4 inch added to the length of the blade ? It also appears to me from the pictures you posted one of your L 58 knifes has an aluminum guard ? Western used aluminum and plastic guards on knifes because of the shortage of brass during and after W.W. 2 until the brass became more available .Also I don’t see the L58 listed in the 1950 catalog pages so I think the knifes most likely had a short production run .possibly 1947-49 ?

Thanks, yes, some have steel guards, with thin black and thick red WW2 type spacers.
Am thinking the brass was used after WW2 on these, Just a guess.
Have also seen these with steel guards and bakelite pommels.
Do not have one of those yet...