Russ 1980s vintage plaid shirt *like new*

This shirt is in EXCELLENT condition, doesn’t look like it’s ever been worn! Still has plastic tag in armpit. Union made (ILGWU tag dates between 1975-1995) White button down short sleeve shirt with red, blue and purple plaid pattern. Women’s size medium (?) Width: 20” across Length: 13” pit to hem (at the side/shortest) Materials: cotton/poly?