Now that is an interesting bit of history to add to the discussion!

It might also be worth pondering whether more modern (especially American/western) style belts got reversed with the extra length to the left, in order to draw one's pistol from a holster which is typically worn on the strong-hand side (except for cross-draw, of course). And I don't really want this discussion to get de-railed or shut down due to weapons discussions, but I think it's pertinent to the topic. So enough said on that aspect.

At any rate, it's interesting food for thought. It could be that belt direction has gotten mixed up between different cultures, as it were, due to different functional needs, and by this point there is no firm standard. But as it relates to the kilt belt that doesn't really have extra length exposed outside the belt, it may be a bit moot. The functionality is not affected by which side it buckles from; it's purely a matter of making sure the belt and buckle work together. Do we know if there was a traditional/historical direction that these were typically built to follow?