Not the same James Smith signature.
But your James Smith family may have had same named individuals in parallel lines, or even a father perhaps?
Or a coincidence, the harder one looks, the more alternative connections, sometimes can be made.
James and Barbara Box, had a Son John baptised and James Box, Occupation was given.
----------
There is another James Box, who left a Will, Proved 1780 PCC, who was a Smith and a Brazier of Brook Street, in the Parish of St George, Hanover Square, Middlesex.
Requesting to buried in the Burial Ground at Paddington.
My Sister Jane Box now residing in Brook Street.
Reference to property in George Street, Grosvenor Square.
My Daughters Jane Box and Margaret Richards.
My Grand Daughter Jane Richards an Infant Daughter of Margaret Richards ...
(See also Voters Poll 1770s on Anc).
Will
https://discovery.nationalarchives.gov.uk/details/r/D383880Added
[ ]th March 1776
Joseph Richard, Bachelor, married Margaret Box, Spinster.
[All signed & he signed Joseph Richards ]
Present (wits) Thos Trimlet ; Sarah Trimlet.
Marriage Indexed as 11 Mar 1776
Saint Dunstan And All Saints, Stepney: Rectory Square, Tower Hamlets, England
1770
Thomas Trimlet married Sarah Richards