Video from Yuri Pasholok.
This is a 45mm 7-33 anti-tank gun, developed by the No.7 Plant in Leningrad. It’s based on Model 1927 76mm regimental gun and was locally produced in Leningrad during the siege. It was found and recovered from the Nevsky Pyatachok area, a tiny bridgehead (2km wide, 0.5 to 0.7km deep) that was a place of heavy fighting. During one year and a half, 70 thousand Soviet soldiers and officers lost their lives on that small piece of ground trying to break the siege, many finding their death in the cold waters of the Neva river. They all knew what they were getting into and what their chances were – and they went anyway.
The entire crew of this particular gun was killed there and the gun itself was shot to pieces. After the war, it was recovered and restored to the current condition thanks to the efforts of the staff of the Russian Military History Museum near Moscow, but the battle damage was kept for all the museum visitors to see and understand: such is the price of victory.