No. Russia wouldn't have had the T-34's in '39. Granted the germans woulda had weaker tanks as well, but they woulda been fresh off their non-agression treaty. Hitler would have just had to wait untill the Russians got mired down in Finland and they probably could have reached Moscow.
Also, I think you're underestimating the effect of allied strategic bombing. Also remember that had England not declared war on Germany, she might have been willing to do trade. Churchill didn't much fancy the communists and thats a fact.
IMO, worst case scenario is that Germany looses poland and East Prussia, with the Russians deciding that the well defended german lines aren't worth charging.
Who knows, without the factories under constant air attack, germany MIGHT have finished the Maus. I don't know how likely it is, but its sure as hell possible.