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Trish is not currently online, but I found Joseph's likely birth and death details when I was searching before, but I didn't add it to this post as I thought you just wanted general advice; I didn't want to spoil the search for you!
I cannot find a death for Joseph or Sarah Lincoln in Purleigh, which suggests they moved away.
If you search for children born to a Joseph & Sarah Lincoln post-1760 in Essex, you find:
Joseph (1762) in Purleigh
Jeremy (1767) '' ''
Edward (1768) '' ''
Then a gap of 8 years before:
Sarah (1776) in Woodham Walter.
Searching for a burial for the parents in the Woodham Walter area, brings up the following:
Joseph Lincoln, aged 86, buried on 23rd November 1813 in Woodham Mortimer. Would give him an estimated birth year of 1727.
Sarah Lincoln, aged 75, buried on 15th May 1808 in Woodham Mortimer. Would give her an estimated birth year of 1733.
I don't think there are any other Joseph & Sarah Lincolns in Essex who would fit the above other than the parents of Edward.
Queenie
