Twin-turret T-26 (with machine-gun armament) crossing a river during combat training of the Moscow Military District forces, 1936. The vehicle has a riveted hull, with welded & riveted turrets 
A T-26 with a welded hull and welded right-hand turret. Moscow
Military District maneuvers. 1933 
A twin-turreted T-26 undergoing upgrading. Kubrnka 1940 This photo gives a good view of the road wheels introduced on later model vehicles.
A mechanical service is being undertaken to the twin-turreted T-26 from the first half of 1932 production series (with riveted hull & turrets). Moscow Military district, summer 1934. Note that the muffler was fixed by with 2 clamps 
Twin-turreted T-26 mod. 31 and T-26 mod. 33 with radio station and night lights. The 35th Light Tank Brigade, Winter War, Feb. 1940 
T-26 mod. 1931 knocked out by German troops (the vehicle's plate number "8314" is painted white on green background). Uktaine. July 1941.
Twin-turreted T-26 tank with gun & machine-gun armament during manoeuvres in the Moscow Military district 1934. The tank has riveted hull & turrets.
Double-turreted T-26 tank with mixed armament and equipped with radio transmitter No. 7N type during manoeuvres in 1934. Coil antenna is mounted on the hull of the tank .
The first twin turreted T-26 tank equipped with 37-mm B-3 gun. The vehicle incorporates a number of common elements for tanks constructed in 1931 - riveted turrets, muffler fixed with 2 clamps, lack of jacket above air outlet. 
A twin-turreted T-26 armed with the PS-1 cannon. The auxiliary
gun shield on the weapon is missing. 
T-26M32 with twin turrets and mixed armament (gun & machine-gun). Modification of the beginning of 1932 
M. Kolomiets, M.
Svirin,"T-26 Legkiy Tank" Frontovaya Illystratsiya, No 1, 2003
M. Kolomiets. "Tanki v Zimnei Voine 1939-40", Frontovaya Illyustratsia, 3/2001
M. Svirin, M. Kolomiets, "T-26 Light tank", part 1, Armada,
T. Abashidze, I. Moschansky, "Kievskaya Strategicheskaya Oboronitelnaya operatsia. Part 1. Tragedia pod Umanju" , 2003