Hello Judy - I don't think this is going to answer your question, but if you haven't seen it there's listings for different Johnstone families and the farmers at Broomhill in 1797-8 in the Dumfriesshire Farm Horse Tax Rolls. I appreciate that's a bit later than you wanted to look, but it is quite interesting.
http://www.scotlandsplaces.gov.uk/digital_volumes/image.php?book_id=545&image=E326%2F10%2F2%2F142 My family are from the same area, and when I was posting on this board looking for old maps to identify some of their farms and addresses I got directed there from NormaTrees. Beattock is the Kirpatrick Juxta parish, but in this it's listed just as 'Kirkpatrick' although Kirkpatrick Fleming has its full name.
There are 2 possible Adam Johnstone births listed in Kirkpatrick Juxta.
One is December 1703, father David Johnston, and the other is May 1704, father William Johnston. Without looking at the originals I don't know if they are birth dates or baptismal dates, but you can see the originals on Scotlands People - they would be just 5 credits each, and if you are lucky might give a reference to the farm or similar where the family lives (David Johnston of ... , for instance).
For the 1703 the GROS reference is : 838/00 0010 0012
For the 1704 it is 838/00 0010 0012
You could also re-do the search putting David instead of Adam and see if you get a common father.
(
p.s. that last line could have been better put - I meant if two baptisms showed a father in common, not that any of the Beattock families were common!)
