Background for others who may help;
1841 Census, Eltham, Kent, we have William and Elizabeth age 65.
Both not born in Kent
HO107/482/8/Eltham
1851 Census he is down as Wm age 28. Actual image is;
Wm Blaxton, 78, Father, Alms People?, born N.K, West of

?
HO107/1606/465/16
So born c 1773