Hi Jannie
Checked out your John Isaac Carter on the micro fiche at Luton library. Isaac Carter c 26.1.1851 Stotfold son of John & Ruth Carter. The entries around this date were very faint but seem to tie up with the IGI entries. John was a labourer. The following may also help.
Marriage 24.7.1847 Stotfold
John Carter full age bachelor, labourer of Stotfold father Richard Carter, labourer
= Ruth Brown minor spinster straw plaiter father James Brown labourer
Both x (left their marks) Wit: James Brown x, Emily Carter x.
3.5.1857 James Carter 24 bachelor labourer of Stotfold father Richard Carter, labourer
= Mary Ann Rowley 21 spinster of Stotfold, Margaret Rowley single woman now married to George Hewitt, labourer
James Carter signed, Mary Ann Rowley x Wit: John Carter x Elizabeth Carter x
29.6.1867 Thomas Carter 19 bachelor labourer of Stotfold father John Carter labourer
= Mary Ann Anderson 19 spinster of Stotfold father James Anderson labourer
Thomas Carter x Mary Ann Anderson signed Wit: Alfred Anderson x
Martha Carter x
2.10.1869 Samuel William Pratt 23 widower labourer of Newnham father Reuben Pratt labourer
= Martha Carter 23 spinster of Stotfold father John Carter labourer
Samuel William Pratt signed, Martha Carter x Wit: John Childs Rebekah Pratt
13.12.1879 Caleb John Howard 22 bachelor labourer of Stotfold father John Howard labourer
= Phoebe Carter 19 spinster of Stotfold father John Carter labourer
Both x Wit: George Gentle x Charlotte Jane Pratt
24.3.1883 Benjamin Hyde 21 bachelor labourer of Stotfold father Charles Hyde, carpenter
= Eliza Carter 20 spinster of Stotfold father John Carter labourer
Both x Wit: John Howard x Phoebe Carter x
Regards
criggy