Lou Levov
I think that it has to be J.K. Simmons. He is 52 and could maybe be made to look old enough to be the Swede's father circa 1975. Whenever I pictured Lou's rantings I thought of Simmons in the Spiderman films.
You might want Eugene Levy for the role. He would certainly look more Jewish than Simmons.
What do you all think?