The 1st image came from the Drake website where they have that 8-bore for sale. They describe it as faux damascus.
http://www.drake.net/products/Westley-Ri....-1850?id=28575

I have handled such guns and they are obvious once you become aware of possibility. In some cases, the exterior was actually painted on.

1900 would be a bit late for the faux damascus, but not impossible. By then the Belgian law strictly forbid any barrels that were faked to marked as damascus.

The picture looks like the result of the Sachs Patent #410678, method of ornamenting barrels.


Pete