Thanks Leighton. Your barrels demonstrate a couple of interesting things. The thicker breech segment of the right barrel is apparent in the difference in the colouring. It is not Greener's 'Silver Steel' but the usual British Laminated Steel which is a "puddled" mixture of as much as 4 parts steel to 1 part iron, and produces a mosaic pattern rather than the linear pattern shown above.
Here is 'Silver Steel' that Craig refinished


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