That sheath did not originally come with that knife. I don't know what the knife is, but the sheath is "very, very similar" to the style of sheaths that Camillus shipped with their Western W49 Bowies and Remington marked W49 copies that came with delrin handles.
Go on fleabay and do a search for Western W49s. Depending on what's currently listed, there are 5 kinds of sheaths for the W49.
The earliest ones (1963/4 - 1968) have a handle strap and no dangler.
The next version (1968 - 1978) have a handle strap and a dangler.
The next version (1978 {B YC} - 1984 {H YC}) have a handle strap, dangler and the word WESTERN stamped on the sheath
The next version (1985 {I YC} - 1989 {M YC}) have a handle strap, a dangler and COLEMAN WESTERN stamped on the sheath.
The above were all produced by Western/Coleman-Western in Boulder (1964 - 1977) or Longmont (1978 - 1989), Colorado.
The next version (1991 to 2005) was produced by Camillus somewhere. They are like yours - dangler, no handle strap, guard strap and a rope script WESTERN stamped on the sheath.