Hugs far I have found the breastplate Sir Hanush wears in a treasure cache in Sassau (Decorated Cuirass) I know you can get a copy of Lord Capons doublet in the upper castle in rattan along with the tight red hose which are best for sneaking.
I am at a loss why sir Divish doesn’t wear his ornate armor in the conversations before battle though.
Though allot of people change armor in cutscenes too. Like robard and some of the bandits at the windmill.