Well I don't know if this is your man but I have found a James Robb in the 1901 census living at
13, Friars Street, Stirling, Stirlingshire, Scotland and place of birth is Stirling
His occupation is given as plumber and he has a wife called Elizabeth born 1877 at Dollar, Clackmannanshire.
You don't state where in Scotland James was born so don't know if I have found the right one.