What is it, and how do I wear it?

[OC Richard]

Good find!

So St Kilda has it in production

https://stkildastore.com/Double-Brea...ade-to-Measure

I would quibble with calling it a Prince Charlie, however. What we call the Prince Charlie was originally called "the Coatee" and later "the Prince Charlie Coatee".

And the Prince Charlie is indeed a proper coatee, due to having the tails of a coatee.

This St Kilda jacket, like the ones the Alexander Brothers wore, is not a coatee as it lacks tails.

I would, rather, call it a Montrose with open lapels. (The Montrose ended at the waist all round.)

Here is the British military coatee worn c1800-1855, which the Prince Charlie Coatee was clearly copied from.