During the Great Patriotic War, a mounting of 15–40 mm appliqué armour on about a hundred different T-26s was performed by local factories in Leningrad in 1941–1942, during the Siege of Odessa (1941), the Battle for Moscow and the Siege of Sevastopol (1941–1942). A cutting of armoured plates was more rough than developed during the Winter War; the majority of these modified tanks did not have a moving armoured gun mask as seen in Factory No. 174's original design, and some tanks had front appliqué armour only.