Locks on the case date it to much more recent than more vintage. (I'll say vintage as 100 yrs.+) So, it still may be 50+ years old. Rounded corners are certainly more recent when plastic was used. Be interesting what's under the underside of the lid? The inside lid photo looks somewhat odd - Like an insert has been added? Have to agree that it looks more like embossed leather or even leatherette / vinyl. Just remember when it comes to a vintage look, most everything has been copied/duplicate/imitated.
Can't imagine more than a std Browning case is worth. $300 +/-.
Interesting though.