vintage Native Traditions by Allen Wah vest S

Preowned but an excellent condition. Tag on the inside shoulder says 80% cotton and 20% rayon. I think that is the woven front. The back feels like a satiny polyester. Size S- measures approximately 18 1/2 inches pit to pit and 20 to 22 inches long. Vintage – I think this is from the 1970s or 80s?