Well done Igor.
Did you see the discussion here about early British fluid steels?
http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=482352&page=2Wm. Powell & Son used Whitworth for barrels in 1875. The first Purdey Pair Nos. 10614 & 10615 were delivered January 1, 1880 with the “New Whitworth Fluid Pressed Steel”. Lefever Arms Co. was the first U.S. maker to supply Whitworth steel for their Optimus in 1887. Parker Bros. used Whitworth for the first AAH Pigeon Gun in 1894 SN 79964 delivered to Capt. Du Bray. Hunter Arms first offered Whitworth on the Monogram, A2, and A3 in 1895.
Sir Joseph clearly won the marketing war, but it is my opinion that by the 1880s Siemens-Martin steel was very good stuff and likely used on many more quality British doubles.
A third chart in the 1891 Birmingham Proof House Report is frequently overlooked, and was generated based on the cumulative grains of powder plus the grains of shot yielding seven “First Class” barrels:
English Steel, Siemens – Martin process English machine-forged variegated Damascus, 2 rods
English “Superior Barrel Steel”
Foreign Steel, Siemens – Martin process English machine-forged best Damascus, 4 rods
English machine-forged chequered Damascus, 2 rods
Foreign Steel
“Second Class” was English steel, basic open hearth process and English steel, Siemens – Martin process; special mix.
The Phase One winners, Whitworth and Laminated Steel made up the “Third Class”.
And no Krupp samples were included in the Trial.
And why no mention of Sergei Aleksandrovich Buturlin's
Drobovoe Ruzhze Istrelz Ba Iz Nego?!?
BTW: your much appreciated and valuable translation thereof MAY appear in the upcoming Summer
Double Gun Journal
Feel free to use anything here for Part 2 of your article
https://docs.google.com/document/d/1dnRLZgcuHfx7uFOHvHCUGnGFiLiset-DTTEK8OtPYVA/edit 
