Answer by Tom Lindholtz
Since no one with the qualifications you seek has risen to your request, here's two bits from the Peanut Gallery.
I'd start with Thomas Sowell. He's not as "old" as you're apparently looking for, but I think he has several benefits to what it sounds like you're trying to accomplish. With respect to your time frame, I'm inclined to think that we are now living in the golden age of conservative thought. That notion could be expanded, but it's beside the present point.
I think Sowell is excellent because he is adept at stating his case in terms that are not overly academic. He has an abundant archive in the form of short columns on a wide variety of topics. And, in an era when it is a knee jerk assumption that Blacks are always liberal and Democrats, he stands as a towering intellect who is a Black conservative. So, in addition to the excellence of his arguments, he may also serve as an icon and role model for some students who desparately need a good one.