Could you please direct me to a source that says Eston Hemings Jefferson claimed to be the son of TJ, as you say, in the mid-1800s? For Madison Hemings, we have the famous post Civil War/Wetmore newspaper article. But I could find nothing that refers to Eston himself claiming to be a son of TJ. ~Thank you!
Isn't the sequence of Eston's family history reversed in your last bullet?
Your last bullet states:
"Eston Hemings's descendants, who have lived as whites, have passed down a family history of being related to Thomas Jefferson. In the 1940s, family members changed this history to state that an uncle of Jefferson's, rather than Jefferson himself, was their ancestor."
Didn't the original, contemporaneous oral history state that the family had descended from an uncle or relative of Thomas Jefferson, and not Thomas Jefferson himself?
And then later (in the 20th century) the family was convinced by others (strangers) to change their own history to claim Thomas Jefferson himself as their ancestor? You have this sequence listed in reverse.
It is significant that the original story was descent from an uncle or relative, but not from Thomas himself.