Sir Robert Mclellan of Bombie(Lord Kirkcudbright) and the Robert Maxwell of Orchardton (and the Maxwells of Hazelfield, Blamangen, Newlaw) were all closely associated and intermarried in a tangled web. In fact Robert Maxwell d 1681 1st Baronet m #2 Marion McClellan...there are several Maxwell and McClellan marriages....there is alot of info online. Hope this helps.
Don Maxwell firstname.lastname@example.org
from: Galloway Levellers (use Google book search)
Charles I madeRobert McLlelan Lord Kirkcudbright in 1633. 62 After the death of Robert McLellan in 1639, the title passed to his nephew Thomas McLellan and then to Thomas' son John who died in 1664. Following John's death, Sir David Dunbar I gained possession of the McLellan lands in Kirkcudbright parish. The McLellan's Irish lands passed to Sir Robert Maxwell I of Orchardton, husband of Sir Robert McLellan's only legitimate heir, his daughter Margaret. They had four children- Robert, Hugh, Thomas and Anne. Robert II inherited in 1671. In 1688 he was in Killelagh parish in County Londonderry from where he wrote to his nephew concerning the management of his cattle park at Netherlaw. After Robert II's death in1693, his brother Thomas (who was a lawyer) inherited the Irish lands. After Thomas Maxwell died, his widow Isabel Neilson (a niece of Robert Neilson of Barncaillie) married Patrick Heron II (1672-1761) of Kirroughtrie in 1721. McKerlie gives the details.On the 5 August 1715 Thomas Maxwell had sasine [of Cuil, Buittle parish]. He was a lawyer, and his actions tarnished his reputation. He marriedIsabel,daughter of [William] Neilson merchant, Dumfries, brother to the laird of Barncailzie. He had no family, and at his death his widow married Patrick Heron of Kirouchtrie, parish of Minnigaff. Among other things he had the estate of Ballycastle, Londonderry, Ireland, conveyed to him in trust by his cousin Sir George Maxwell of Orchardtoun, parish of Rerwick, giving a bond that he wouldconvey it back to Sir George in liferent; to his wife, Lady Mary, Dowager Viscountess Montague, if she survived him; then to the Earl of Nithsdale and his heirs male; and failing them, to the third son of the Earl of Traquair. However,instead of adhering to this, along with Cuil he conveyed the lands not his own to his wife Isobel Neilson on the 14 October 1720. "The Laird of Cool’s Ghost" wasthe subject of a small chap-book.