Disco Stu,
The 317 Trailblazer was a contract knife made for Buck by Camillus from 1972 through about 1990 when it was no longer listed in the Buck catalog. Many were made over the years and this folding hunter style knife came with a black leather sheath during most of its run. It may have originally been offered sans sheath. If you want to know more about the 300 series knives, look for my article in the Jan 2000 issue of KNIFE WORLD. It can be found in the Modern Collectibles section. The 317 originally had
a tang stamp of BUCK / MADE IN / U.S.A. Then, in approx 1972 or 1973, the tang stamp was changed to read BUCK / 317 / U.S.A.
I hope this helps!!
Larry