Thanks for the help J.J. I did think about spelling variations but was unsure about the variety, so I did it the hard way !! I just looked for Johnston, then Johnstone. That took a "few minutes" as you might imagine but still no success. Perhaps my mind is too regimented, but when a search engine allows a search AFTER a given date, I do not expect it to go back 20 / 40 years with answers. In any event, I have, as suggested , asked nicely for their help. I will let you all know the outcome.
Rob