Hi, Mike,
This is remarkable! It may take me a little while to get back up to speed on this, as the last posting was nearly 4 years ago, and I need to pick up the thread again...
However, I have since discovered that Robert CARTER) (senior)'s wife was an Elizabeth VANE, and her family came from this area of Kent, I believe. I'm still not quite clear how "Mill Hall" was given as a birthplace for Robert CARTER junior in 1824. I wonder whether it referred to the estate rather than the grand house itself. Certainly the CARTER's were fairly prosperous wholesale furniture merchants in the Minories in London by then, but I doubt whether the family could have been associated with the main house.
Perhaps if you have any details on Mill Hall that might throw some light on this matter, I would be most grateful. Also, too, any photographs would be gratefully received! I'll PM you with my e-mail address after I've written this,
Very best wishes, keith