Vintage Granny square thick chunky crochet sweater big buttons size large

No tags. Likely handmade. Amazing crochet granny square jacket. Main thread color is navy blue. Squares done in green yellow blue red and purple. Four large crochet buttons. Good vintage condition- one dark stain on one of the sleeve cuffs, not very noticeable with business of fabric. See picture. Approximate measurements laying flat 23” pit to pit 23.5” long E