I believe this information came from
The Parker Pages, but may need to be revised
The latest damascus barrels:
SN 220,657 GH D3 1927
SN 222,845 DHE D4 1927
SN 227,020 VHE D3 1928.
Regarding Parker Bros. fabricated pattern welded barrels
The Sportsman's Gazetteer 1878
http://books.google.com/books?id=bow...AJ&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.
The ‘PB’ proof mark has been found on Decarbonized, Laminated Steel, and Twist barrels in the SN 950-4650 range; much earlier than the 1877-1880 time period in which Parker offered “figured barrels”.
More information at the bottom here
https://docs.google.com/document/d/1...4S6OIN1bA/edit