The only Pre ZW mod for T vs T I know about is the T34/76 one made mostly for MP but that also modified the first Soviet single mission replacing the T34/85 by a T34/76( one has to be a masochist to do that...)
. You can find it on the Tanksim.ru download site. I never tried it personally.Other mods are MMP3, MMP4, MMP5 made by MP modders and tweaking the game to give the Tiger a faster reload rate and a slower one for the T34/85 as per historical data. I downloaded both because although I don't play MP the change apply to SP missions as well. They are a welcome change to the original game which aimed to balance the odds.You can also find the same download on the tanksim.ru site( you can translate downlaods and instructions into English).