I enjoyed reading the story.
The first time I heard about Milton Friedman was in 1981 when I was still in Poland. I mention it in my article “Capitalism versus socialism.” You do not need to read the whole essay; the relevant paragraph is at the end of the section titled “Socialism and me.”
Milton Friedman did not bill me for the email he sent me in 2006. He liked my story. With reservations, he supported my views about immigration. At least, he saw it that way. His secretary told me he did not want me to make his email public because he had received a flood of critical emails, some not nice, when expressing a similar opinion previously.
Please note that his abstaining from speaking openly about immigration reflects the dynamic of inner circles among political writers he told you about, but you questioned it.
I waited a few years, and after Rose died, I decided there was no harm in publicizing that email.