Summary: this is a used Johnson roughback sheath for a Randall model 20 Yukon Skinner. The sheath is correctly stamped "20" below the Randall trademark on the back of the belt loop. Looks like a previous owner added a hole for a handle lanyard, no big deal. Darkness at the throat from past knife storage, handling marks on both sides.
4 photos for review -- as shown, an unused Fine India sharpening stone is in the front pouch. This is a nice used sheath in excellent condition, a great find if you’ve got an old model 20 missing original leather. Thanks and good luck.