I just received an email from Alexis Malcolm about the US Army tartan. Here is an excerpt:

Art has just returned from 18 months of duty at West
Point & while there he lobbied the Director of Music
to get the US Army Tartan accepted by the Army as
their official Tartan. He had a call yesterday from
the Director to tell him that it had come down from
the Pentagon that the Army is now in the process of
doing just that & its status will be official shortly.