Delphian Arms Co. was a tradename used by Supplee-Biddle Hdw. Co., Phila.; on Crescent sidelocks, and Hunter Arms Fulton boxlocks c. 1920.
If a Crescent, the barrels should be marked 'Genuine Armory Steel' and 'Choke Bore'. The Fultons were marked 'Peerless Steel' and 'Made By Experts' - wow! wink