Hi suffolk suepip,
I said to my wife after putting my post on the board "I wonder how long it will be before someone shoots me down in flames"
I had a feeling about William 1 and from your post it looks as though his family may have gone back to Cavendish. On my next visit to the UK and Essex (2008), I'll have to try and fit in a trip to one of the Suffolk Record Offices to check if a William and Elizabeth Theobald had any children baptised at Cavendish after 1772. I won't give up hope on him yet but nor will I be holding my breath.
I was aware of the Borley marriage, I'm fairly confident the groom was William Theobald son of Samuel and Elizabeth, he was baptised 18 Oct 1773 at Borley.
Well it still leaves William 2 firmly in the picture (for now), although I expect it will be a devil of a job to track his mother down, finding his father probably impossible, although he might have been a William!!!. Unless I missed something, Elizabeth doesn't appear to have been baptised or married in Gestingthorpe, I didn't have time to check burials. Wouldn't be at all surprised to find she was sent from another parish to give birth to William, perhaps quite a distance from home, possibly even shipped in from over the border in Suffolk!
My William named his first daughter Elizabeth and as there are no Elizabeths in his wife's family that is possibly a clue to his mother's name, since both William 1 & 2 both had mothers named Elizabeth that clue is not much help in this case!
Thanks for your help, even though it dashed my hopes somewhat, it is appreciated.
Regards