What catches my eye, with that knife, is the 4 handle pins in the stag - 2 at each end. Seems like most of Case's older fixed blades with handle slabs usually had two pins - one at each end. A collecting guide* I refer to shows a model 5025-5 in stag that very closely resembles the general shape/form of the handle and blade, the mushroom pommel, and specifying a 5" blade. And the one photo in the book shows 2 pins on the handle. Looking further around the web, I did see an old auction listing (Worthpoint) with pictures of a 1920s-'40s model 5025-5 in stag with 4 handle pins, looking very similar and with a 5" blade. The stamping on that example was different than yours, likely for an earlier era ('CASE' w/long-tail 'C', over 'TESTED XX'). But the stamping on yours looks similar to a 1940-'65 stamping (for fixed blades) shown in the collecting guide, with all the letters in 'CASE' of equal height (or very nearly so), no 'tail' on the 'C', etc.
I AM NO EXPERT on these beautiful old knives. But I couldn't help but grab the guide and start paging through it, when seeing your post.
* - The Official Price Guide to Collector Knives, by C. Houston Price, Fourteenth Edition (2004)
