Here is the Will & Testament of Simon McTavish.

Tho' he was called the "Marquis" by his employees, they would not have said it to his face for fear of losing their positions. And accused of ruling with an iron fist he was kind-hearted to his nephews - William, Duncan & Simon McGillivray. They in return had lots of respect for him, as I do too.
http://www.garthbeg.com/willofsimonmctavish.htm