1st - I noticed this was your very first post - so, Welcome Aboard Catball87! You didn't list your state (or country) in your profile. So, you might consider jumping over to Sub-Forum: Select Your Area.... for information (i.e., clubs, hunts, finds, legends, maps, etc.) directly related to your state (or country).
2nd - How about some dimensions (helps search) AND on the side (your third picture) - does that "door" open?
To me, it appears your case was constructed to carry a specific item.
The loops on the side of the case are probably where you would clip on a shoulder strap.
Based on the lock and the case design, it appears to date from the 1930s to 40s.
Dave