I saw @OC Richard post a neat thread about his new spats for his impression of a pipe major from the Black Watch (fabulous job, by the way, sir). It got me thinking.

What would a pipe major in the Highland regiments wear when deploying abroad through the years?
What would they wear now?
Would they defer to another MOS (military occupational specialty; I don't know the correct terminology used in the British or Commonwealth armed services) and lay down their pipes when deployed?

Thanks, gents.