Dave,
I have a Sherrifmuir (I guess I spelled that right) jacket, which is at the same formality as the Montrose. I plan to wear mine to the upcoming Burn's Supper. These are usually very formal jackets/white tie affairs, and because of their price, few people have one. I got one because The Scottish Lion was closing and had one a half price. Typically this jackets are worn with a lace jabot and lace cuffs. Now the Sherrifmuir fastens at the top, and the rest is open. The Montrose is buttoned all the way up. I have seen very nice pictures of the Sherrifmuir worn with a black waistcoat, high collar wing tip shirt, and one of those old fashioned victorian style black neck ties. To me in my opinion (so take it for what you are paying for it),this dresses it down just a little bit to fit in with black tie dress.

David