Does anyone know if at any time due to this that he would haven been awarded Polish citizenship?
Did he ever go to communist-controlled Poland after the war? If he didn`t, it is impossible he was granted the citizenship coz such things had to be dealt with personally. Even if he was granted the citizenship by the Polish government in exile, I doubt it was recognised by communists in Poland.
Check at the nearest Polish embassy or consulate, they have such data.