I have not seen a Buck,with the single blade in that pattern __ Case makes a ""TWIN"" of the Buck 317 & has a single blade model___the Buck 110 single blade,sorta took over as the number one single blade,as Buck Company grew **
Hoyt Buck made the first Buck folding knife (Model 117) in 1946 ( very rare ***)___actually he just made the blades and put them into handles from war surplus lifeboat knives ___ In 1963 the 117 was redesigned to make the model 110__which made the company into ,what we know today ***
Your friend could have a the secondary blade removed or just but a Case 6165
Good Luck__Monk
