SWISS STGW. 57 RIFLE BAYONET AND FROG

This knife - bayonet is used on the renowned 7.5 mm. Sturmgewehr 57 selective-fire rifle (the Rolls Royce of selective-fire rifles), made by the firm Schweizerische Industrie-Gesellschaft (S.I.G.).  

The Stgw. 57 had a very long service life, remaining in production from 1958–1983.  A later example, with the simplified blade marking. "V" above the serial number identifying the blade supplier as Victorinox.