John Davis suggested 1877-1879 with SNs 10,000 - 16,000

The Sportsman's Gazetteer, 1878
http://books.google.com/books?id=bowCAAAAYAAJ&pg=PA680&dq
PARKER GUNS.—From the day when the Parker gun won the First Premium at the Centennial Exhibition until now, it has held its pre-eminence among American guns. The arm is simple, durable, and effective. All have Rebounding Locks and Interchangeable Parts. Twist barrels $50 to $75. Damascus $75 to $300.
This is the only firm which manufactures their own barrels.

https://docs.google.com/document/d/12y9006Ur7mMCqdeeye89c7L4DQrc2iXR8p4S6OIN1bA/edit