Vintage '60s/70s women's knitted shirt

Vintage ‘60s/70s mock turtleneck ladies knitted poly/nylon striped top. Tagged M, though fits much smaller (see measurements below). No brand tag. Near mint condition/very light wear, with all original buttons intact. Measurements (keeping in mind it does have a considerable amount of stretch): 12-1/2” shoulders 15” pit to pit 7” sleeves 21” length