Vintage gray green tweed double breasted blazer jacket

Vintage gray green tweed double breasted blazer jacket. 4 light brown buttons, 2 front flap pockets with fun lining fabric, fully lined. The original owner placed a sweet St. Bernard dog pin at the collar, which I’ll leave on it. Likely 70s or 80s. One small spot that is a little threadbare- seen in pics. No size or maker tags- best for a medium or small- dress form is a 6/8. Measures (flat, unstretched, approx): armpit to armpit: 17in, waist: 16.5in, hip: 16in, shoulder to hem: 23in, sleeve: 20in menswear academia