A Crest of Masters family?

[Mike_Oettle]

Just for clarification, CT, the black lion within a black royal tressure on a gold field is the clan coat of arms, and not a crest at all.
The crest (which probably belonged to the clan chief, or to its senior representative) is the device within the strap and buckle: the hand holding the ducal cap, with laurel branches on either side.
The blazon quoted on the website does not mention the rose above the cap, although it seems also to be part of the crest.
The crest-wreath, or torse, should always be shown with the crest unless it is replaced (and specified as such in the official blazon) by a coronet or similar device.
Any Buchanan (or, in this instance, a Masters) may display the clan crest badge, or wear it on his bonnet. The crest by itself is a different beast, however.
A Masters or Buchanan who has his own coat of arms may, however, display his personal crest instead of the clan badge.