Is2 in game with the isu-is2- allied warmachine copy ability (note the map too, it somewhat resembles a now present 3v3 map, but it seems to be a older version of Rhzev)

A good look at the old overlay..

Here another one of the overlay, with what I assume were the three original soviet commanders, before they went all DLC.. (you can also see the t2 had a different design back then, barbed wire and spikes around it!)

I also remember, from aplha that is, that Elefant and if I am correct even the Tiger tank were buildable from the HQ or T4 buildings. But they somehow changed them and said it didn´t work that well. I believe they changed it because they had to scramble commanders to sell for sega..
ps. I also remember the ISU152 being named the Beastkiller and Beastkiller alone.