At 22:38, during the meeting between Archer and Huth, the painting on the wall is Renaissance masterpiece "The Flagellation of Christ," by Piero della Francesca.
Barbara says she was 18 when her father's paper sent her to cover the fighting in the Chaco War between Paraguay and Bolivia. That war took place between 1932 and 1935. Assuming Barbara was sent to cover the fighting soon after it broke out, then she would be about 27 at the time the series takes place. Later dates and therefore a younger age for her seem less likely.