T-26 m1931 / T-26A
 

spob35 - Finland

Unit 005 T-26 M31
Weapon 1: 13.2mm M/30 TMG
Weapon 2: 7.62mm DT TMG

After some googling it would appear that some T-26 Model 1931 tanks did indeed have a HMG in the second turret. However I am pretty sure all Finnish T-26 Model 1931 tanks had just the 7.62mm DT machine gun in both turrets.

source:
http://www.jaegerplatoon.net/TANKS3.htm#T26A

Re: T-26 m1931 / T-26A
 

Still it would be interesting to hear more from others about this. The books that I have know only of two different T-26 m1931 versions. The most common version has the 2x7.62mm DT MG arnament and the second version has a 37mm gun in the right turret and a 7.62mm MG in the left.

I wonder if the 12.7mm HMG version that is in the Soviet oob was just a prototype that never entered full scale production?