In your view, must a tartan waistcoat always be cut on the bias? Must it always be from the same cloth as the kilt? Should it be worn with day wear or simply to add flourish to an evening wear ensemble.

I ask because I have a five button waistcoat that is very old and while it's in the same tartan as my kilt, the colours are faded, the white is yellowed and the set is smaller. Also, it is not cut on the bias.

Would wearing this with a newer kilt of a larger set be considered bizarre in the Highlands or given it's heirloom quality, is it a look that would seem fairly normal or within the bounds of traditional if not typical for day wear.

I'd love your input on these questions.