When you can’t decide what to wear, begin with your waistcoat. It was clearly the focus of any well-dressed gentleman’s outfit in the 1890s and beyond. Actually, they got started, in London, much earlier than that. Though the origins of many popular articles of clothing remain ambiguous, the waistcoat’s first appearance in English society is dated precisely: 18 October 1666. To Court, it being the first time his Majesty put himself solemnly into the Eastern fashion of vest changing doublet…