If you're after the birth certificates of him and his father PM me.
And if anyone knows why his brother was called Robert Ballantyne Brunton, born 13 Apr 1839 then kindly share, as the name Ballantyne seems to have arrived from nowhere.
We know his father kept up with Scottish naming conventions with his children, "William Tait" Brunton I can account for but "Robert Ballantyne" Brunton !!