OK.
Found them in 1901 Scottish census, Nathaniel jnr born Rutheran, Rubestin (Rutherglen?), Nathaniel(about 35) and Jane, parents, also born Glasgow. Have you got a birth for Nathaniel jnr from Scotandspeople?
Father Nathaniel born 1865 Bridgeton.
His father Francis born about 1845 Ireland. (According to censuses).