Hi
Have been off-site for a few days and just noticed your post.
The name Roan is still fairly common in Kirkcudbrightshire and is quite distinct from Rowan and other variations.
Some of the Roans migrated up to Ayrshire and changed the family name to Rowan for some unknown reason, possibly because the Registrar was more familiar with the Irish name Rowan as they moved over from Ireland.
There is a Loch Roan and several place names where 'roan' is part of the name.
the earliest we have located my wife's family name is from the Will of a Samuel Rowan or Roan in Stroanfreggan near Carsphairn in 1780.
If you search on site for Richard Jamieson you will find another Roan - Janet (or Jessie) marrying him in 1862.
We have a William Roan m Catherin Wright in in Carroch Toll bar in 1841.
If any of these names rings a bell PM me.
Russell