Bill: that information came from David Trevallion. Are you confident the barrels are original? 102XX would be about 1877.

Sir Joseph Whitworth, Miscellaneous Papers on Mechanical Subjects: Guns and Steel, 1873
https://archive.org/details/miscellaneouspa02whitgoog
On p. 18 Whitworth states that the tensile strength of No. 1 Red Gun Barrel steel is 40 tons/89,600 psi, the same number claimed by Henry Bessemer. No mention is made of carbon content or composition.
Daniel Kinnear Clark, The Mechanical Engineer's Pocket-book of Tables, Formulae, Rules and Data, 1893 reports 67,000 psi for Whitworth gun barrel steel.

Sir Joseph's adaptation of Bessemer's principle of hydraulic pressure casting was patented in 1874.

Wm. Powell & Son first used Whitworth steel for barrels in 1875 per Stephen Helsley.

"Damascus Explained" thread is now 11 years old, and many of the images have been lost in the photobucket abyss and internet space frown
http://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=74750&page=1
and Steve Culver has 'splaind it a lot better
https://docs.google.com/document/d/1jQPuv4yOXpTppdXkAiyGj6LC5bXDAYBCR1DME9lB0JM/edit

https://sites.google.com/a/damascusknowledge.com/www/home