Hi there, the info I have for the couple is as follows.
John Stanbury married Fanny Matcham 31.3.1823 St Pancras, both single, of the parish and signed, witnesses James and Jane Matcham, both signed. Then children as follows.
Ann bp 31.10.1824 (born 25th Aug) Marylebone, father’s occupation ‘Trade’, abode Marylebone; ’poor’ is written in first column of the register with dittos underneath.
John George bp 14.5.1826 (born 22nd Feb) Bethnal Green, father’s occupation Labourer, abode ‘B. G. Road’.
Grace Frances bp 6.1.1828 South Hackney, father’s occupation Labourer, abode Martha Street/Cambridge ??; possible burial for Grace Stanbury 4.8.1836 St Pancras, age 8 years (born c. 1828) abode Cheney Row.
John James bp 29.11.1829 (born 3rd Nov) Old St Pancras, father’s occupation Scavenger, abode Edmund Street
Jane bp 10.2.1833 (born 23.10.1831) St Pancras, father’s occupation Dustman, abode China Row
Samuel bp 10.2.1833 St Pancras father’s occupation Dustman, abode China Row (double baptism with older sister Jane)
Mary (Stansbury) bp 18.9.1836 St Pancras (to John and Frances) father’s occupation Scavenger, abode Chenies Street
Francis bp 11.8.1839 Old St Pancras, father’s occupation none (line in column), can’t read abode
William * bp 11.4.1846 (born 20.5.1841) St Pancras, father’s occupation Carman, abode Agar Town
* Birth registered as William Henry Stanbury Q2 1841 Pancras RD mmn Matcham.
In the 1841 census, they’re in Lower Union Place, St Pancras, and all born in the county (i.e. Middlesex).
John 45 carman
Fanny 40
Ann 17
John 11
Jane 9
Samuel 8
Mary 4
Francis 2
William 1 month
Have you checked if there’s a baptism record for John Stanbury (say) 1790-1800 in Middlesex?
Also, how is it known that he was a miller born in Devon? All his children’s baptisms say he was a labourer, dustman or carman (as does the 1841 census).