But then again, the 1851 entry is a bit of a mish-mash!:
David Strang 70, shoemaker, b. Kippen Perth
Jannet Strang 26
Mosses Strang 17
Address: Kippen, Stirlingshire.
I'll check the 1861 census and see whether he was till alive.
Added: Can't easily see him in 1861, may have died by then. Have you looked for his death cert between 1855-61? 1855 was the start of official registration in Scotland. If he died before this year, it will be hard to formally verify his parents as no death cert. including this info will be available.
Monica