Combat Engineer's Knife with original rubber scabbard and frog, by the Trud Factory, early 1940s.
Factory sharpened 165 mm long blade is maker marked З-д ТРУД ВАЧА ("Trud Factory, Vacha"). The blade is 4.5 mm thick near the hilt which is standard for the Trud Factory combat knives of the period. The grip is in hardwood, polished very smooth and stained brown. The scabbard and integral frog are in black rubber.
In outstanding, excellent condition, probably unissued. The blade is clean, free of notches or wear, and shows only a couple of small areas of surface pitting - no significant rust or other serious damage (please note, the blade was covered in protective Cosmoline while in storage and the residue will appear on it again after it's sheathed - very easy to clean off with soft cloth). The rubber scabbard shows only storage age, completely sound and pliable, free of cracks, with fairly uniform color. The steel button attachment of the frog belt loop is intact. The grip is perfectly preserved, completely free of cracks, chips or scratches.
This weapon first appeared around 1940, probably as a result of experience of the Finnish War, and was manufactured exclusively by the small Trud workshop in the Village of Vacha. Officially designated a combat engineer's ("sapper's") knife, in reality it became a part of standard kit of Soviet NKVD Spetsnaz.
Among collectors in Russia, it is generally known as "Saboteur's Knife". Later during the war, it was apparently phased out in favor of the NR-40 "Scout's Knife", and original examples are very hard to find - especially in premium condition such as this example.