seems this is a tough one I agree it does looks like the T26 chassis. Doesn't seem like it could be the 76.2 mm gun though, as the barrel should be visible from the angle it's photographed. The SU-5-1 (1st of Small Triad series, utilizing a modified T26 chassis) tested 2 different versions of the 76.2 mm gun (model 1927 regimental gun) and (model 02/30 divisional gun.) The SU-5-2 mounted the 122 mm divisional (model 1919/30) howitzer. The 3rd version was the SU-5-3 which was armed with a 152 mm mortar. Supposedly, 15 of these were produced (5 of each sub-type) but in the end they were rejected as to being costly to build and not providing enough of an advantage over existing artillery and support tanks such as BT-7A. So after all this, I'd guess the SU-5-2 with 122 mm howitzer.
Your on the right track, but that's not correct. I'm not familiar with the ISU 155... did you mean the ISU 152 or was the 155 an experimental/prototype I'm not aware of?
It's a KV chassis quite early as there is no cupola just what looks like 2 periscopes, The upper superstructure is cast not welded, not seen that before, great post
IIRC they did a number of SP attempts on the KV chassis besides the KV-7 and SU-152, but nothing I've seen has that cast superstructure look, there are two "missing links" I know nothing about KV-10 and KV-11, the KV-13 was the "universal tank" from the KV design bureaux.
Depending on the source there appears to be some question if the KV-7 variant 1 was designed as a flame throwing tank. A little more info here on the KV series. KV-3, KV-4, KV-5, KV-7, KV-9, KV-220 - BATTLEFIELD.RU -
Quite right. Photo from http://mailer.fsu.edu/~akirk/tanks/swe/Swe-Landsverk10-IonFonosch.jpg Here you go! Regards,