Years ago, I took a Damascus refinishing class out in Colorado at Trinidad State NRA summer session taught by Mark Beasland. There were about 15 Students who brought about 35 barrels to work on that week. We brought project guns that we could afford cheap to learn. One of them was Belgian faux Damascus. Mark said that one or two show up every year he teaches a class.
http://firearmshistory.blogspot.com/...s-barrels.html
Here is a link to a succinct explanation of how they were made. Cheap iron tubes. Some of these clunkers still survive.