Hi,
I'm new to this site, but came across it because I did a search for North Court, Abingdon on google and found this thread. It's quite hard to follow all the ins and outs of the people you're talking about, but my gggg grandmother was Mary Fletcher, married to Samuel Williams. I'm related on my maternal side via their daughter Martha Williams m to James Collier; their daughter Martha Leader Collier m to Charles Hemming and so on down the female line.
I have a family tree done about 30 years ago which concurs with your discussions, although it doesn't go back quite as far. I have Benjamin Williams married first to Elizabeth Buckland who died 21 Feb 1800 and then to Sarah Edgington on 23 Dec 1800 from whom he had all those children!
I actually have a couple of photos of North Court, taken circa 1865 (according to the writing on the back) One has 2 women in it and it says on the back "Grandma Green in the seat at North Court, Abingdon (Elizabeth Leader Williams Collier). But as the inscription is probably later than the photo and there seems some confusion which Elizabeth it is, I'm not sure how reliable it is. I'm happy to attach a copy if anyone is interested (my scanner is broken so it'll have to be a digital photo).
I also have a portrait of Martha Collier (Hemming), although that might not be of interest as it's later than most of the people you're discussing (1860s?) so probably not such a close relative, but I'm happy to photograph that and attach it if it is of interest. I'd be interested to know more about your investigations and how you fit in.
Regards,
Jenny