If that is an "O" above the crossed swords (the mark is upside down in your photo) in the lower left hand corner of the flats, the original year of proof was 1934, according to the linked Hallowell & Co. proof date codes.

http://www.hallowellco.com/proof_date_codes.htm

A very nice looking gun with beautiful scroll & game scene engraving.

Norman & Sons may have actually finished it, or perhaps more likely ordered it from the trade with their name engraved on it.