Vintage 80’s St. John gray button sweater Santana dress belt removable collar

Vintage 80’s St. John gray button midi dress leather belt removable collar. Santana knit. Feels very soft. Could have a blend of another fabric but there are no fabric tags. Elastic waist. Hidden front buttons. Thick adjustable leather belt with chunky triangle buckle. Marked size 8. Made in USA. GUC. Collar is removable. Could also be worn as a headband. Measurements taken laying flat are approximately: Pit to pit: 18” Waist: 14.5” - 21” Hip: 20” Length: 45” Sleeve: 22” Belt is 3” wide and 38” long Belt is also GUC but there is a little scrape on the leather at the buckle (shown in photo - not noticeable)