FV201 - note its Centurion Mk.II turret and a 17pdr gun. The first picture shows the comparison with Centurion.
Official description: "T-34-85, used in the shooting of the movie 'Four tankers and a dog'. In the movie, it represented a T-34-85 tank of the 1st Tank Brigade of the Polish Army "Heroes of Westerplatte" with the turret number 102. In real life, it was a Polish-produced T-34-85 with some differences from the late war Soviet vehicle. In 1951, production license was acquired by the Polish factory Bumar Labedy in Gliwice, Poland"
Picture shows comparison to the regular T-34-85
Comparison of the AMX-30 and Leopard 1 sizes
Object 244 comparison to the original IS