Ron,
I've got to agree with you on the Civil War Cavalry Greatcoat for warmth and for wearing with a kilt. I have both a US (like you are wearing) and one patterned after Maj. Gen. John Bell Hood's overcoat in what the reenacting community calls "British Army Cloth", a dark blue grey mixture. Very warm, cuts the wind, and I can access my sporran with no trouble at all, while wearing it.

Cheers,

Brian