There was an
Isaac MESSENGER listed on FamilySearch with the same parents as Charles and baptised Coleshill. I do not see him on the 1851 census and still have not found any of the family in 1841.
Here are the baptisms with parents John MESSENGER and Susannah
JOHN MESSENGER, born 18 June 1821, baptism: 30 Aug 1822 Over Whitacre, Warwick, England (John snr was born in Over Whitacre)
Ann MESSENGER , baptism 15 JUN 1834 Coleshill, Warwick, England
Charles MESSENGER, baptism 21 SEP 1832 Coleshill, Warwick, England
Jane MESSENGER, baptised 17 JUL 1830 Coleshill, Warwick, England
Isaac MESSENGER, baptism 6 MAY 1836 Coleshill, Warwick, England (verified from image - father's occ miller)
There are others with parents John and Susan which I'm not sure about. MESSENGER is a common surname in those parts
However Thomas and Elizabeth are both living with father John in Coleshill in 1851
Thomas MESSENGER, baptism 02 NOV 1822 Coleshill, Warwick, England
Susannah MESSENGER, baptism 11 MAR 1828 Coleshill, Warwick, England
Elizabeth MESSENGER, baptism 18 AUG 1825 Coleshill, Warwick, England
Sarah MESSENGER, baptism 08 APR 1824 Coleshill, Warwick, England
Free BMD has this death, Sep qr, 1838
Susannah MESSENGER, reg at Meriden, Vol 16 p241 (Meriden registration district includes Coleshill)
Aha - found some of them in 1841 living at Over Whitacre
Chas Messenger 8
Ann Messenger 7
Isaac Messenger 5
in same household:
Wm Boddington 55, butcher
Catharine Boddington 55
Mary Boddington 20
Wm Boddington 20 Wheelwright
And here's Isaac 1851
Back of 261 New John St West, Birmingham
William Ray 20, jeweller
Jane Ray 20 wife, b Coleshill
Hariot Ray 14 sister
Isaac Messenger 11 brother-in-law, errand boy, b Coleshill