Theres no liner in the sheath just a welt.
In case you don't know a welt is a strip of leather sanwitched between the front and back leather which keeps the blade from cutting through the stitching or lacing...ect.
Here are a few that I’ve done. Don’t know how authentic they would be to the fur trade era, but I like them. Top is a broken Ontario Butcher: the second down is a Utica Butcher that I re-ground; the third down is one I made from a buck saw blade and walnut with 16 penny nails as pins; the bottom is a Green River blade with ebony macassar. It’s a fun hobby that I only have a few dollars in. They make good kitchen and camp knives which I don’t mind throwing in the dirt.