Not being that familiar with the old Marlins, I'm not sure what a saddlering carbine would look like. I just ran across an ad for a barrel in 32/20 for the 1889 or 1894 Marlin. It stated that the barrel is in new condition with bright blue at 98 to 99 percent. And that it had never been on a receiver. It didn't specify if it was octagon or smooth. Also it didn't specify the length, but I assume the carbine was a standard length.