I know it has been a number of years since you posted your message on Genealogy.com but I have started to help a friend research his family tree and have come across the name Porteous. His Porteous family include William George Porteous (1881-1962)married Mabel Beatrice Ivin (1882-1956). We have been unable to go any further back on William George Porteous' side.
Is this the same family you are researching? We would love to hear from you. My email address is firstname.lastname@example.org