Hi Clare/irret
I agree with ireet this is the only Joseph at the right age on the 1851 census.
I have transcribed the village myself and note a couple of differences.
H.O.107/1740/05 Pg 10 Folio 496 Sch 38 Nether Heyford
Joseph Mann Head Mar 50 Shoe Maker Weedon Nth
Charlotte Wife Mar 40 Heyford Nth
William Son U 17 Shoe Maker Heyford Nth
Joseph Son U 14 Heyford Nth
John Son 11 Heyford Nth
Sarah Daur 08 Heyford Nth
George Son 07 Heyford Nth
Fanny E Daur 05 Scholar Heyford Nth
Richard Son 02 Scholar Heyford Nth
William P Grandson 01 Heyford Nth
Frederic Son 01 Heyford Nth
Cheers Sandy