Vintage sequin sweater black gray ivory diamonds sequins

Vintage sequin sweater. Black knit with gray and ivory harlequin diamond pattern. Diamonds are completely covered in iridescent metallic sequins and beading. Long sleeves. Crew neck. Pullover. Padded shoulders. No size or brand tags. Guessing a medium based on measurements of my other vintage sweaters. Please review measurements: 21" from underarm to underarm laid flat. 26" in length from shoulder.