What level of dress would you classify this?

[MacMillan of Rathdown]

I agree, the modern "evening" and "day" sporrans hadn't evolved yet. If men didn't wear hair sporrans, what did they wear? I don't see much evidence of anything being worn but hair sporrans.

Actually there are lots of examples of what we now characterize as "day wear" or "evening wear" sporrans prior to the mid-19th century rise in popularity of the horse hair sporran as an item of civilian attire. But, and this is important to remember, as Jock has pointed out, in the mid-19th century Highland attire was something that was almost exclusively a middle-class and upper class indulgence. Many of the Highlanders themselves lived in the most dire conditions of poverty-- dressed in rags, as Jock put it-- and totally unaware of the then current fashions in Highland attire as worn by a minority of the more well-off portions of Scottish society.

Did men back then fuss over what was "proper" for day wear, smart day wear, black tie, white tie, etc.? Did those conventions even exist amongst Highlanders of the day? I doubt it.

"Back then" is a rather sweeping statement, but if, for the sake of discussion, we draw an arbitrary line at 1837 (the year Victoria ascended the throne), then yes, those who dressed (as opposed to those who merely put on clothes to work in the fields or factories) did fuss over what was proper. We see this in Victorian literature-- Thackery, Conan Doyle, Dickens, Jane Austin, all are at pains to describe (often in excruciating detail) the every day dress of their characters and to comment when they were not properly dressed for the time of day or the occasion.

You can bet those conventions existed for the few in Scotland who wore Highland attire; morning dress is morning dress whether kilted or in trousers, and evening dress would be the same for all gentlemen, kilted or otherwise. Loudon Douglas MacQueen, writing before the First World War (The Kilt, a Manual of Scottish National Dress) was a Victorian gentleman, writing at the end of the Edwardian era, who was at pains to pass down to future generations the conventions of Highland attire. So yes, "back then", the few men who could afford to wear Highland attire "fussed" over it just as much as someone new to Highland attire today should "fuss" over getting it right.

Since the 1960s and 70s there has been an explosion in the popularity of Highland attire, and more people wear Highland attire today than at any time in the past. This is, in my opinion, a good thing. That fewer people take the time and effort to "fuss" over the way they wear Highland attire today, than at any time in the past, is, in my opinion, an unprecedented and unfortunate state of affairs. I'm not talking about the personal eccentricity of wearing a horse hair sporran for day wear with a jacket and tie-- that's fine-- but rather I lament the sloppy and often slovenly way in which Highland attire is worn due to ignorance or indifference.

Something that did not happen "back then".