Vintage CASE pocket knife from an estate sale out of Lancaster Ohio.  
 
Hard to find SINGLE BLADE "Case XX", "5158L SS".  Plain blade with no hammerhead or shark etching.
 
Made in 1991.  LARGE 4 1/4" KNIFE WHEN CLOSED.  7 1/4" long when fully open.
 
Blade has no signs of use.  The brass has some light signs of age.   Everything works as it should.  The sheath is as close to brand new as you can get.  SEE PICTURES.

 
Location E2