Charles James Blair is my gt grandfather via Edgar. I don't have any information about Eva other than her birth, so anything you can let me know would be good. (I have 10 children for Charles and 12 for James Cummins Blair)
Regarding James Cummins Blair I too am wondering about his place of birth. I have a baptism entry in Downpatrick, Ireland which could be him, and his brother John was also born in Ireland as were his parents James and Jane. I haven't found any link to Scotland, but as you mention it is listed on some documents.