I agree Greg - we know what they could do during the cold war era, but it would be interesting to see how many they could produce at the present time.
It seems to me this is a bit of an academic question since no country has the Cold War production capability these days. Even the Chinese manufacturing has been cut down because copying even the 80s models of T-72 is far more complex then the T-55s they used to do in the 70s.
I dare say that tanks are taking a back seat to more offensive weapon systems these days, mostly air delivered, and the nature of threats has changed for the European powers and the USA.
In fact the greatest possibility for use of armour has shifted rather dramatically from Europe to Asia, and the most significant additions to tank fleets have been there, with China, India and Iran all buying from existing manufacturers and attempting indigenous design and production programs.
I appreciate this is a bit off the topic, but in looking at the strategic situation today, it seems to me the situation is not a lot unlike Europe of 1930s with several large economic powerhouses that are seeking to express their political and ideological points of view.
Unfortunately for Europe and the USA the 'view' from the outside in(to Asia) is not quite the same as the 'view' from the inside out. The actual strategic mass of the regional participants can assume a velocity and trajectories of their own that may prove to be beyond control of most of their governments as happened in Europe in 1914 and 1939.
In Asia though the superiority of the air-delivered weaponry is not as challenging to the tank as it is in Europe, so we may yet see clashes of the 'steel beasts'.
I'm not sure if the T-90 will be involved, but it is of note that the only Russian division fully equipped with the T-90 is stationed in the Far East (Siberia).
Cheers
Greg