I see that he is a clerk by 1841 but that doesn’t make him wealthy
My thought too.
Having a servant doesn't either. Even working class people had servants.
As for being a Gentleman this may apply to anyone above working class who usually had independent means but not always.
As a carpenter he may have regarded himself as upper working class. The Vautins may have been lower middle so not much of a glass ceiling to break through.
He had a career in the Bank of England, moved upwards by the look of it. The Vautin family were certainly not poor, doing OK. As active and committed non-conformist Christians, they would live and behave modestly, and would look after their finances responsibly.