Vintage gold maxi dress with floral trim

I bought this at a high end LA vintage shop for $250 and I love it but don’t have many places to wear it. Have never worn it besides around my house. It has no tag but the boutique owner told me where/when it’s from, but I can’t remember it. If anyone knows? Love it to bits and would be happy to hold onto it for the right occasion, hence the price. The material is hard to explain. It’s metallic feeling, but completely comfortable enough to wear without anything under it and it’s has stretch 🤯! Measurements are approx as it stretches. No tags. 20” width 53” long