1950's (Kay) Windsor archtop.
Serial # L875 6866.
Notice that original plastic tuner buttons have evaporated and crumbled off.  Their Kluson tuning machines are in excellent condition.
Notice that I have marked a red line on the photo to show the gap that can be opened at  the neck joint due to it's hide glue releasing and the the neck joint free in it's joint machine tolerance.

The neck joint continues up to the base of the fingerboard (marked with red line in the picture on the right), with a base plate matching the neck behind the joint and under the fingerboard.  This makes a neck reglue / reset a very easy job without having to remove the fingerboard and/or a fret or fret-marker to release the neck joint.  Releasing the fretboard from the baseplate should free the entire joint.
The nearest I can determine is that this is a Kay archtop from their 1940-50's K40-series archtop guitars, and sold as a jobber to what contract I haven't been able to determine yet;  Likely Sears or Montgomery Ward.  If anyone knows please let me   know.

In any event, this guitar is really cool and sounds great.  Solid Spruce top with figured maple sides, back and neck.

Needs easy neck reset and tuning machine buttons replaced.

With the above repairs the Guitar will be 96%+ Excellent+