My father was partial to the mess jacket when kilted; he liked them because there were no buttons in the back to get caught on dining chairs! I may have a photo of my father, brother, and self, and if I do I'll post it as it shows three distinct types of formal jackets all worn at the same event-- my brother's wedding!

As to the velvety fabric your jacket is made from, my guess is that it's doe skin, an ultra-fine wool.