Thanks very much for the information. Knew the birthdate of Irving Sr and had some info on his wife and a bit of info on Irving Jr. Did not know about son, Raymond. Middle name of Simpson is that of his paternal g-grandmother and middle name of his uncle, George Simpson Cleghorn.
Irving Sr was first born of Adam Cleghorn and Isabella Richardson - my g-g-grandfather and mother. Have not found register for his birth so far, but Adam was working in Moffat in 1867.