The closest I can find to a match is Jules Evrard, but there is no information about this maker. So, they may not even be in the correct time period. Smith had the same sources as the other makers of this period. So, it very well could have been a contract from Belgium that was farmed out to lesser makers because of work load.
Alex, you asked about redoing the barrels. I would, it is not that expensive. It would certainly bring out the pattern even more.
I believe Geno to be correct. It is some type of chain damascus, which is what I first thought when I saw them. However, not having another example.... Yes Geno, we do miss Oscar at these moments.
Drew,
Here is some trivia for you. It seems the Walloon gun makers often used coffee in reference to work. "The coffee is so thick you can cut it." "You have to whistle for your coffee." Translated to, "I am buried with work." "I have no work."
Pete