Hello Paul and Mike.
My scan of the mark came from Rodney and Janice Dietert's book on Edinburgh Goldsmiths.
I'm embarrassed to say I got carried away with the eraser feature when I enhanced the scan. Also included was the word "unfreeman".
After looking at the other marks listed in appendix C (additional Edinburgh marks) it occurs to me this might be his early mark, before he became a freeman.

Could not find any more information on Matthew Craw in the book.
Pat.
.