waistcoat vs vest

[Downunder Kilt]

From the small image I would say that you are wearing a Argyll type jacket. As far as waistcoat/vest, it depends and where you hail from. They are one of the same item and can broadly be defined as a jacket without sleeves. The other type that you refer to is what can be seen at white tie events where one wears a marcella fronted false waistcoat. If you visit the Gentlemens Emporium website you will see a wide variety of waistcoats/vests. Cheers and all the best with your project.