Jock Scot, pithy and valid points you have. Apologies if I have overcomplicated this.

I shall endeavor to borrow your terminology and rephrase my question. If in the realm of traditional/classic Highland apparel there is a continuum ranging from historical to modern, where is the conceptual division?

Examples are welcome but I think I'm trying to elicit more of a guiding principle... as a young, North-American man, I lean towards what seems modern and away from what seems historical. Nevertheless, I have great respect for tradition and am not interested in modernity stripped of its roots. I think my parallel question of how people have formed their sense of style is intended to be supportive to this larger question.