Clanranald has a pedigree that predates the Sobieski-Stewart Bros. if I'm not mistaken although it was included in the VS by them, but that doesn't matter anyhow. MacLean of Duart Hunting is almost certainly one of their fabrications, but it has been accepted by that clan and is no less a clan tartan than anything else.

Speaking as a Clanranald MacDonald myself, I am always a little giddy when non clansmen are attracted enough to the tartan to wear it, proud. You've my blessing.