This rifle is pretty much a big mystery - I have virtually no good information on it. Through inspection, we know it is a mechanical copy of the Soviet SVT 38 or 40 - it shares the same exact bolt, locking system, and gas system. Even many aesthetic features like the metal front handguard, muzzle brake, and sights are remarkably similar to those of the SVT. The biggest difference is the magazine, which is a fixed design fed only be stripper clips. The rifle is chambered for the 8x59mm Breda cartridge, and magazine capacity is unknown - probably either 9 or 10 rounds.
The clue that this is a Pavesi rifle comes from the safety lever, which is identical to the safety lever on the Model 1942 Pavesi rifle. The only markings on this piece are two repetitions of the serial number (875), on the receiver and stock. This serial number suggests that a significant number of these rifles may have been made, although I have not seen any other examples, nor any recorded information on when or where they were made, tested, or fielded.
The most interesting diversion from the standard SVT construction is the addition of a leather buffer pad on the back of the receiver. This was clearly added after the rifle was built, as it must be removed before the bolt can be taken out of the action. The details of the receiver cover attachment were also modified from the original SVT, making disassembly and reassembly easier, with the mainspring less prone to kinking as in the SVT.