In 1714 two portraits were painted of his "Champion" (i.e. body guard) and his piper wearing it, and it bears no resemblance at all to the present Grant sett. Reconstructed thread counts from the portraits vary slightly, and the reconstructed setts are known as "Grant Champion" and "Grant Piper".
Will, very interesting -- the Piper to the Grant Chief you mentioned was one William Cumming. The Cummings and the Grants were "neighbours" and at one point adversaries (Lord Strathspey still has a skull of the one of the Cumming Chiefs as a trophy at Castle Grant) before serving as pipers. I'd like to see the "Grant Piper" tartan.

Cheers,

Todd