One family to keep a note of from 1851/41 as a possible for John's family (you have his parents' names names from his MC?):
1851:
Elizabeth Hamilton 62, boot binder b. Belfast
John Hamilton 19, ap. tailor b. Belfast
James Fisher 26, son in law, iron moulder b. Glasgow
Jane Fisher 24 b. Belfast
Address: 72 Kirk Street, Calton Glasgow
1841:
Elizabeth Hamilton 40, shoe winder
Margaret Hamilton 20
Isabella Hamilton 15
Jean Hamilton 14
James Hamilton 14
John Hamilton 9
Robert Hamilton 3 b. Lanarkshire
Address: Kirk Street, Barony
Monica