Hi Rhade I have my doubts about the existence of that variant, I saw a photo on internet that could be fake or simply someone found it practical to transport a Renault 35 chassis and a T-26 tower in the same train car, also add that modifying the chassis of a vehicle with a smaller ring than the tower to be installed is quite complex and requires mayor work, in addition to issues such as weight, balance and internal space, I do not doubt that it was an idea but I doubt that someone carried it out, (scale models are not a reference either) well those are my reasons for not including it, perhaps in Alternate Universe section.
Best regards,