Years ago I bought a box of "junk" at a yard sale from a widow of a WWII vet it had some little odds and ends in it shells and things but once i got it home I found two knifes in it the first turned out to be a German SS officers Dress dagger made buy stiletto. the other is this CASE hunting knife no other I.D marks other than the name CASE. the Leather sheath says CASE XX that's it. looks to be the original sheath. i have put in some photos to help. any info would be awesome.
The knife you have is either a 523-5, or a 523-6 Overall length 9" or 10 1/4" repectively. I agree with Philco regarding the Era. I had one just like it not long ago. The pommel of the knife is the small square. Case hunting knives with the round or square head pommels were converted over to the knights head pommel during the XX era.
Philco the knife you show is the same knife but has the Knights head pommel. This pattern could be from the XX or USA era. If it has a pattern number on the back of the tang it would be from the USA era. In the USA era all Case hunting knives had the Knights head style pommel with the exception of pattern 557 SAB.
Source: Knives & Razors, 6th Edition Jim Sargent. Bradley Wood, the author of fixed balde Hunting Knives