I can't say how the American services view the wearing of their tartans, but certainly here in Scotland I was permitted to have a kilt made in Royal Air Force tartan in honour of my late father's service, so long as it was pleated to the sett. The fabric was only available through the RAF's supplier, Strathmore Woollens whose kiltmaker also built my kilt. From memory they were more relaxed about supplying the tartan for export - Riverkilt was able to obtain his as fabric which he was then free to have assembled by Kathy Lare in the USA as a pleated to the stripe kilt.