This is just a guess until you are able to confirm father Robert's parents' details but going by his age and place of birth, this is a possible census entry for him in 1851 - everyone showing as born in Dumbarton, Dumbarton except for mother:
John Mccormack 36, stater (?slater)
Eliza Mccormack 29 b. Kirkcaldy, Fife
Ann Mccormack 9
Isabella Mccormack 7
John Mccormack 5
Eliza Mccormack 3
Robert Mccormack 1 b. Dumbarton, Dumbarton
Address: 17 Hill St, Glasgow
Monica
