42nd highlander regiment double breasted doublet in Crimea.....

[OC Richard]

Would it be correct that...the Piper Muir photograph shows a double-breasted doublet without Inverness flaps, in Black Watch tartan, and kilt and plaid with the Black Watch Music Tartan?

Muir's doublet clearly has the tashes/Inverness skirts. You can just see them under the dirk.

They show up better here, you can see the tashe, the button, and the loop of Soutache braid going to the button:



A terminology thing, only if a jacket has tashes (literally "pockets") AKA Inverness skirts all around is it a Doublet.

(Piper of the 93rd. At far right the shell jacket can be seen.)



Here's a colour representation of the short-lived 1855 doublet, note the dirk belt is worn under the doublet.

(Officers of the 93rd.)



Coatees have skirts in the back and are straight and waist-length in the front. They were worn in the army from 1800 to 1855, and revived a century later, in 1953.

(Pipers of the Black Watch.)



Then there are Shell Jackets, extremely popular in the mid-19th century, which end at the waist all around (no skirts of any sort).

They were worn as an Undress jacket in Victorian times (officer at right).