This is the correct version of the asymmetrical Malcolm as shown by the woven sample in W and A Smith's 1850 publication 'The Authenticated Tartans of the Clans and Families of Scotland'. Their provenance was "We addressed Sir John Malcolm of Balbeadie on the subject of his Tartan, and enclosed a specimen, which the worthy Baronet acknowledges to be correct." D.C. Stewart notes in his Nomindex "Remarkable similarity to the Double Davidson."
This tartan dates to 1850.