Thanks - this ties in with the information I have, but unfortunately I don't know any more about Archibald. I know a bit more about his wife Margaret Palmer (1819-1894) and their son Richard (about 1860-1933). Archibald's father was probably Richard too - they seem to have been very traditional in their naming throughout the generations - and they probably came from Dublin, which is where most of the Rocks in the South seem to have been based. All specultation unfortunately...