If you might be aware, Hugh MacDonald was the name of Sir John's Father. Hugh married Helen Shaw. I suspect that Hugh was not your direct relative, however, highland tradition of names means a lot of familes passed down of the grandfather's name to the grandson. I do have a lot of information Sir John and access to some people who do have even more. If your research leads you in his direction, drop me a note and we can see if we can help.
Paul MacDonald
Hays, Kansas.