Foreign military vehicles to add to US units for variety

[Olefin]

Actually the Soviets had border installations that consisted of old German and Soviet WW tank turrets on top of concrete bunkers.

Also there would be another place you could find old WWII tanks that could be put back into action - there are tank museums in the Soviet Union, Poland, Germany, France and Czechoslovakia- any of those nations, later in the war, may have raided those collections to find any tanks that were still workable - even if it was only the turrets and they dragged the tanks into place to use them as pillboxes.