John,
Have you tried Find a grave? There is a wonderful woman transcribing all of Fyvie Kirkyard, her name is Helen Taylor, she is from Fyvie and has just retired. Why not contact her, through the site, if they are there, I am sure she will find them. She also, may be able to short you a photo. This is a very large cemetery on the hillside behind the church. (I have been there a couple of times). Mill Brex, by the way, is the name of your Gparents home in the village of Fyvie. The village of Fyvie is small, today, probably only 500 or so people.

Cathy