What is the best place to buy a bespoke military style kilt?

[OC Richard]

Even if you were a officer could you choose to wear the other ranks uniform?

I don't think it would ever go that far, for one thing officers need to follow the customs of their regiment (and the army as a whole). Part of it was the traditional British class system, a dichotomy between the upper and lower classes. Traditionally officers were drawn from the upper class and dressing as commoners wouldn't have felt right either in uniform or in mufti.

Even in the USA it was unusual that Grant, the highest-ranking general in the army, often wore a privates' jacket and was sometimes mistaken for a common soldier unless his epaulettes were seen.

In the old days British officers purchased their commissions, meaning that Lord So-and-so might purchase a Subaltern's commission for his second son, along with all of his kit.