Hi Donna
In reality, your key verification are the names showing on his death cert. for his parents which seem to match what you have for his family.
I think I can see a number of trees for this family on Ancestry. Are one of these yours? Not sure about the date of birth you have for James. From what I can see, this looks to be the Roman Catholic christening date, not his birth date. One other thing that might be worth looking at. The transcript for the 1841 census for the family shows James and brother as aged 4, ie twins. Have you looked at the original to confirm?
The 1851 census shows James as the elder with a birth year c. 1834 - as transcribed (messy in places):
John Belty 45, labourer b. Queely, Ireland
Isabela Begly 38 b. Fort William, Inverness
James Begly 17, unemployed, b. Pollockshaws, Renfrewshire
Alexander Begly 15 b. Pollockshaws, Renfrewshire
John Begly 12 b. Neilston, Renfrewshire
Archibald Begly 8 b. Barony, Lanarkshire
Address: 75 Macalpine Street, Glasgow
Monica
