Cannot help directly on Anderson, but can confirm millers move around. It depends on the nature of tenure. I had an ancestor who was miller at four mills in his lifetime. Archbank is a farm within a kilometre north of Moffat east of Gallowhill, and by its situation a mill is quite likely. For Kirkpatrick Juxta the main settlement is Beattock, a mile SSW of Moffat, but the parish boundary comes very close to Moffat. Although Eskdalemuir seems a long way from Moffat there were overhill routes between the two, so the interchangeability of family locations is quite feasible.
