No sizing on tag, assumed a small?  Please refer to measurements.

Measurements:

Chest - 35"

Waist - 26"

Length (collar seam to bottom) - 36"

Top arm length - 22.5"

Bottom arm length - 16"

Nice, pre-owned vintage condition aside from a small mark on the back of one sleeve, tiny barely visible mark top front, and tag wear, all shown in photos.