Yes, the 7TP and the T-26 were very similar.
They were based on the British Vickers 6-ton.
The Vickers 6-Ton or Vickers Mark E was a British light tank finalized by Vickers on stockholders' equity (that is it did not result from a national call for tenders). He was not used by British Army but exported or licensed product, in very large numbers. Soviet T-26 is an improvement of the laid off 6-Ton. It was the predecessor of the 7TP in the Polish army. At the beginning of the Second World War, it was the second tank the most spread to the world after the French tank FT Renault.
The tank 7TP is a copy of the British tank Vickers-Armstrong of 1934, the Poles having contented with equipping him with a 37 mm antitank gun and with a diesel engine of 110 cv (it was then the first diesel tank to the world) who could bring him to a 37 km/h speed. He also had a 17 mm armor plating.
T-26 is a light tank of support of the infantry produced by the USSR from 1931 till 1941, about twelve exemplary thousand. Inspired by Vickers 6-Ton, the license of production of which had been bought from the British, it is one of the most successful tanks of the 1930s. He establishes the skeleton of the armoured strengths of the Red Army in 1941, but following the horrifying losses which he undergoes during the German offensive, he quickly loses this role in front of more modern armored cars, and from the middle 1942, he is relegated to secondary roles.
