Hard to tell by looking at just the body. Pictures of the light bulb assembly would potentialy help ID the manufacturer.
In the early 2000's Brinkmann did an authorized copy of an LA Screw Code 4 in a Brinkmann style. Yours looks very, very similar to that Brinkmann. But a peek at the inside would confirm or deny if it's a Brinkmann clone.
Radio Shack also did a similar one and it looks similar to the Radio Shack version.
The ring'd knurling looks like something Bright Star used to do and for a few years they made generic flashlights sold as Bright Star. The only Bright Star named mentioned was on the package it came in. They did some mini mag clones and may have done some Code 4 clones as well.
Does the beam focus like a Maglite? Tailcap have room for a spare bulb? Things like that can help us uncover the mystery here.
To put it simply, I have no idea the vintage or the maker at this point.....