The Will for the William (retired 1815) dated 1824, has been mentioned earlier. I was hoping it would help to trace him back, but it isn't at all straightforward. Have you had any luck with it?
In the Will, William names his niece Jane Gifford Cain wife of Robert Cain of Liverpool. Formerly Jane Gifford. And his niece Ann Allen spinster, sister of Jane Gifford Cain.
Finding the marriage was nice and easy
Robert Cain married 1797 in Liverpool to Jane Gifford Allen
Witnesses George Morley and Ann Allen
There's this baptism, which is a bit confusing. Was John the true father? On the 1841 census, Jane gives her age as 64 (b.1777)
Baptised 21st March 1777 - Bradford, Yorks.
Jane Gifford - father (?) John Allen of Gt.Horton (The question mark is because I can't tell if that is a W. or a Mr.)
And this baptism
Baptised March 1778 - Keighley, Yorks.
Ann daughter of John Allen by his wife Jane, daughter of William Westall, gent. (A very handy piece of information).
Thus, William Westall (retired 1815) had a sister called Jane. So are they the William and Jane mentioned in Richard (dd1760) Will?
If so, I can't find baptisms for them anywhere. Nor can I find a marriage for a Jane Westall to a Gifford.
Looking for a marriage for William (ret.1815) and his wife Hannah. I found one for 1764 at St.Botolph, Bishopsgate. I ignored this at first as I thought it was too early to be them. Then I noticed that the witnesses were Jane Westall and H. Gifford. So maybe it is them.
H.Gifford's name is actually written out in full, but I just can't work out what it's meant to be. It's definitely not Henry or Herbert. Looks more like Hartbowe.
Now I must go. I'm going away on Saturday, and, unfortunately, have loads of things I must do. I would much rather be doing this.