Following on from that 1853 OPR marriage you found, Rosie, which gives James' occupation as 'Nailor'
1841 – Camelon, Falkirk, Stirlingshire
John Fleming, 30, Nailor
Ann Fleming, 29
John Fleming, 9
James Fleming, 7
Janet Fleming, 4
William Fleming, 1
Janet Buchanan, 53
George Buchanan, 15, Nailor’s apprentice
Peter Buchanan, 12, Nailor’s apprentice
All born in county
1851 Glasgow, St Mungo, Lanark 644/1
David Jack, 29, Nailmaker, Falkirk
Rebecca Jack, 25, Wife, Glasgow
David Jack, son, 6, Glasgow
John Fleming, 18, Visitor, Nailmaker, Falkirk
James Fleming, 16, Visitor, Nailmaker, Falkirk