Vintage brocade and velvet dress jacket, smoking jacket

I bought this jacket in the 80's and LOVED it. I still do but it is now too small for me. It's a beautiful paisley designed brocade in gold and black with a black velvet collar. One button closure in front. I used to wear it with black leggings. Sleeves are 21 inches long from shoulder. There is no tag or size visible but I'm guessing it is a medium. I now wear a large and it fits, but it's a bit tight. Length of jacket is 30 inches from shoulder seam. Shoulder to shoulder measures 16 inches. Chest measures 38 inches.