The Parker Serialization book lists your gun as a Grade 2 manufactured in 1884 with 30" barrels in 10 Gauge (not 12ga.). The condition of the stock means you either need to find a replacement, consider the gun strictly a wall hanger, or sell it as a parts gun, assuming the locks and barrels are OK. A collector of Parker hammer guns would probably be happy to pay a few hundred dollars to have the parts.

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