Busy afternoon - until I get to the links let me say re your "bottom line" - they provided very well for their Constitutional qualifications; it was enough that they were citizens, NBC simply didn't apply to them.
Thus, they were Natural Born Citizens, as defined by the Constitution. 🙂👍
You can argue all you want, but history proves you wrong. For the Constitution stipulates that only a Natural Born Citizen is eligible to hold the office of President & Vice President. Since they were among the Founders of this new Nation, they had to obvious be Natural Born Citizens as written in the Constitution. Four of the first 7 presidents participated in the crafting of that Constitution. All 7 were considered Natural Born Citizens of the United States of America, even though the landmass had come under different leadership, as well as, a name change. Citizens before & after the process that had taken place, and all 7 were born within that landmass, before & after the process.
Would a British citizen who came after the landmass became a nation named the United States Of America have been considered a U.S. citizen?
Of course not, they had to go through the naturalization process. Once they became citizens, any of their offspring born after their naturalization process would be considered NBC citizens, while the children born before their becoming officially recognized citizens, were not considered to be NBC but rather naturalized along with their parents.