Many thanks to Pete M who graciously shared a c. 1900 product brochure by a Belgian brl maker. Some detail was lost in the scanning and posting, but it's up now http://www.picturetrail.com/gallery.fcgi?p=999&gid=16082038
Interesting findings include several examples of a One Iron Crolle-Twist Laminate and 5 grades of "Turkish damascus" which appears to be what US gunmakers primarily used, but which was given names like "Boston, Oxford, Washington, American Flag, Horseshoe, etc." for marketing. The Lefever brls in the previous post look like either 1st quality Bernard or Leclere.

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