Polish actress Hanna Orsztynowicz appeared in 1977 in Polish TV at TEATR TV KOBRA - Przerwana gra, wearing a vest. Because of the video clip resolution I'm not sure, but I think it was a denim vest.
Dedicated to all the beautiful women around the world wearing denim jeans vests while the 1970s this may also be some kind of online museum for the jean vests and denim waistcoats, that were an important part of the fashion in the 70s.
French singer Veronique Sanson wore a denim waistcoat lots of times while the years 1974 to 1977. Pictures were found in the WWW.
In the Persian movie Faghat Agha Medi mitoone (فیلم فقط آقا مهدی میتونه) is a short sequence showing a woman wearing a denim vest. It's not possible to see the whole vest, because it is always covered in parts.