I'd like to know how rare my SVT-40 is. It's a 1941 Tula with the serial number СН4525 (so not a sniper version) but with rails on the receiver. It also has a groove in the center of the rear sight, and a 2-port muzzle brake.
That square box on top of the Tula star indicates a post war arsenal refurbishment, meaning many of the parts were replaced after WWII, including the muzzle brake. They simply used the later style when your rifle was rebuilt. It's a very common SVT40 and one that you should enjoy (carefully) at the range! It's more common to have receivers with the rails than without, by the way.
That square box on top of the Tula star indicates a post war arsenal refurbishment, meaning many of the parts were replaced after WWII, including the muzzle brake. They simply used the later style when your rifle was rebuilt. It's a very common SVT40 and one that you should enjoy (carefully) at the range! It's more common to have receivers with the rails than without, by the way.