https://www.ricardo.ch/de/a/militaersackmesser-jg.-1960-sammlerstueck-1133824720/Model 1908 from 1960.
That knife is just a cheap try to create a "fake" soldier knife. The "60" is not a stamp, its an engraving done after assembling. Victorinox did not produce any soldier knife in the year 60, thats for sure. The knife shown is a standard model nr. 200 done for the retail industry, with inox steel (what was never used for "official" soldier knives) and brass pins (also never used for soldier knives). The wk stamp does not mean anything at all. You could order every soldier type knife from victorinox with or without the wk stamp. I dont blame the actual seller of that knife. He wrote that he`s not sure how those stamps/engravings were done. In my opinion, its not a collectable item. It would have been more valuable without the engraving of that 60. That does not mean that it will sell for a lot of money, because people believe always what they want to believe, that its an ultra rare soldier knife missing in their collections...and for sure a proof, that victorinox did soldier knives in the year 1960.