OK Eric - back from the Archives and here is what I have found! Apologies if I repeat what others have already put - I'm going to let you draw your own conclusions about the results. Spellings as entries.
Baptisms at Blyton: -
John Gurnhill bapt 15 June 1798 s. Robert and Ann
Elizabeth Gurnhill bapt 24 Dec 1799 d. Robert and Ann
William Gurnhill bapt 11 Sept 1803 s. Robert and Ann
Thomas Gurnhill bapt 21 Feb 1800 s. Thomas and Ann
William Gurnhill bapt 30 April 1805 s. Thomas and Ann
George Gurnhill bapt 25 July 1807 s. Thomas and Ann
Mary Gurnhill bapt 6 Feb 1810 d. Thomas and Ann
Sarah Gurnhill bapt 18 July 1812 d. Thomas and Ann
James Gurnhill bapt 1 April 1814 s. Thomas and Ann Labourer
Elizabeth Gurnhill bapt 23 May 1818 d. Thomas and Ann Labourer
Charles Gurnhill bapt 28 Aug 1820 s. Thomas and Ann Labourer
Moses and Aaron(?) twins bapt 12 Jan 1824 s. Thomas and Ann Labourer
Possible baptisms of William (Lab) and Sarah's children - at Blyton.
18 Feb 1827 Henry
20 Mar 1829 Charlotte
18 Mar 1831 Harriet
1 Dec 1833 William (William's address given as Blyton Carr)
30 Apr 1836 Eliza d. of William and Sarah GURNEL Lab
11 March (born 14 Feb) 1837 Sarah - as above
31 May 1840 Jane - as above
7 Sept 1842 Charles - s. William and Sarah GURNELL
27 Apr 1845 Elizabeth - as above
12 Apr 1848 Rebecca d. William and Sarah GURNILL
19 Aug 1849 Catharine - as above
Burials at Blyton:-
Charlotte d. of Thomas and Ann on 8 Sept 1818 aged 16yrs.
Martin Gurnhill - 7 June 1836 aged 1 3/4 yrs
Think you have the burials at Glentworth for William and Sarah - I am going to Glentworth next week - I'll see if I can find the gravestones if I have time.
Checked the fiches for Corringham for the Keyworths as follows: -
Baptisms: -
19 Jan 1802 Ann d. of Martin and Sarah Keyworth
19 Sept 1803
SARAH - ditto
14 July 1805 Matthew - ditto
18 Jan 1807 Charlotte - ditto
2 Apr 1809 James - ditto
-- there may have been more!
Also, I got a photocopy of the fiche with the marriage of William Gurnhill and Sarah Keyworth - if you pm me with your e.mail address of 'snail mail' address, then I will scan/send it to you.
Good luck sorting that lot out!
Polly