Welch was virulently anti-communist and he opposed by nearly every lever of the conservative establishment of the day. The then paleocons supported him, albeit quietly.
I gather that your use of the term “paleocon” is used as a negative application, yet the John birch society would be described as the pinnacle of paleoconservative ideology.
What specifically do you take issue with in the paleoconservative perspective? To which item in the below description are you specifically opposed?
“Paleoconservatives support restrictions on immigration; decentralization; trade tariffs and protectionism; economic nationalism; isolationism and a return to traditional conservative ideals relating to gender, culture, and society.[19]
Paleoconservatism differs from neoconservatism in opposing free trade and promoting republicanism in the United States. Paleoconservatives see neoconservatives as empire-builders and themselves as defenders of the republic.[20][21]
Paleoconservatives tend to oppose abortion, gay marriage and LGBTQ rights.”
Including William F. Buckley, whose positive legacy collapsed soon after his death, if not before. National Review practically appeared to support Obama by putting his picture on the cover throughout his first campaign instead of building the Republican talking points, and couldn't have come out more blatantly against Trump, who carried the anti-communist torch in 2015 and today.
Reading the biography of John Birch himself on Wikipedia, it is deeply ironic that his engagement against communists in China was the reason for his death. The course of his life is almost a direct metaphor for the course of America over the past 75 years since WW2. Read it and see. Linked in post 16 above.