Hi pharmaT
I dont think I have Seaton in my extended tree, but Milligan is a very common name in Kircudbrightshire.
John Milligan farmed at Lanecroft from about 1800.
Robert Milligan farmed at Lanecroft from about 1826 until his death in 1856.
The farm was taken over by his sons, William and Robert, who by 1871 had moved to Kelton to a larger farm.
My Milligan family were in the New Abbey Lochrutton area (localities such as Lanecroft, Moorend, Woodhead, Cairnyard, Foreside, Merklandwell, Beeswing, etc.) I tried to attached a map with the localities marked, but it was too big.
Most of the localities have a variety of spellings over the centuries, such as Muirend (early spelling) and Moorend (later spelling).
Lanecroft may well have had a different spelling in the 1700s. However I think "Damcroft" is a different place and is in Kirkgunzeon parish.