"3rd dist" refers to the Third District, or chapter, of the Zionist Organization of America, which at the time encompassed Haddassah (the famed Jewish womens' organization) and B'nai Zion (the fraternal order and mutual support society to which Papa belonged).
Papa worked hard for the Z.O.A., especially earlier in the year when he attempted to revive its moribund First District at the behest of a mysterious supervisor named "Blitz." I don't think these efforts were successful, though; in recent months he's attended a few Third District meetings and one Second District meeting, but he hasn't mentioned the First at all.
Meanwhile, Papa continues to write short, abbreviated passages in a spidery hand, as if some long struggle left him unable to do more than scratch out a few letters. I think this is because the anticipation of Yom Kippur, during which Papa will have to mourn his recently-departed father for the first time, weighs heavily on him. Whether he knows it or not, he is embroiled in a dramatic internal struggle to understand his place in a world without his father and all his father represented. It is probably too much for him to write or think clearly about, but it dwarfs his other concerns.