I think it is a mid-late 20th century build of old and new parts. Barrel, pipes and patchbox look old. Trigger guard and butt plate may be old or new. Lock is newer, agree it's probably Dixie Gun Works. There are three signatures on the barrel, two are old, and the stamped CAD is new. CAD built the gun, I'll bet, and has nothing to do with Douglas Barrels. Just my two cents. Neat gun.