Likely there are few. At Prokhorovka there were only roughly 30-35 Churchills. From memory of photos the Mk III was more common than the Mk IV in Soviet service. The only real difference was the welded turret on the Mk III vs the cast turret on the Mk IV, no difference in ASL. In British service the slightly later Mk IV was more common, many converted later to Mk VI by replacing the 6lbr gun with the 75mm QF.
However note that Soviet documents refer to all Churchills as Mk IV as the Churchill was the 4th British infantry tank design. The Soviets themselves at that time made little note of differences in T-34 models. The various 76mm T-34 might get referred to as "slab-sided" or "hex-nut" in accounts, the m1940, m1941, etc designations are more post war appellations.