Hi there:
on 1851 census s ron at midtown: david 53 farmer, margaret sister 57 and phebe niece 23
on 1861 census at ayr: peter 45 farmer 25 acres, phebe 35, peter 11, margaret 9, john 8, barbara 7, robert 5
you probably have this info but have you tried the" south ronaldsay and burray civil death registers"?