Vintage Big Yank Shirt Long Sleeve Button Down Blue Work Shirt

Vintage Big Yank blue shirt. (not denim) Good pre-owned condition. -Size - I could not find Size, fits like a L or XL, -I think it says 13 /50 ? on the inside collar -Long Sleeve -Button Down -Two Breast Pockets -Two small wear holes on back bottom, pictured -Small mark on back shoulder, picutred -Inside collar is lightly discolored, pictured Length: 29.5” Chest Laying Flat: 23.5”