>>9457383w-well you could always take it from the perspective of using him to get a primary source account for what life was like for an NPC during the pivotal age of America. Don't think about it as humoring him. This about it as having a window to the universe of the "before time" rather than just what kikes and stuff wrote about in history books.
And along the way you can ask the "right" (wrong) questions so that he will be made to realize, through having to provide you answers, how much his generation fucked up.
Think about it as a mental exercise.
And that should make him in an uncomfortable enough position to either stop engaging or you'll be entertained by blowing a boomers mind. I'm sure you should have no trouble being clever enough to ask a boomer the hard-hitting questions to make them realize "oh shit...."