TBH, you come off to me as someone who really looks down on their own nation, by how you say that everyone else looks down on it.I don't think so, sorry. I really believe that even with Brazil putting our blood in the beaches and fields in Europe the rest of the world would still look down on us. They did it with Portugal, Italy and Japan in WWI, Brazil hardly would get a different treatment as this countries had.
This might result in a more powerful left on the post war, capitalising on a mutilated victory.
I have read that FDR did want Brazil on the UNSC, but Stalin wouldn't have it as it would mean another pro West nation on the council. Maybe something could be done about that. Have France get worse treatment, as in it becomes an occupation area, while Brazil takes France's seat, making Stalin not be so opposed as it would be the same number of pro West members, instead of more.