Block of 4 postally used stamps from 1948 with top and bottom inscriptions, cut from SS #582. 200th anniversary of the establishment of regular postal service on the La Plata River. Mail coach, 1854 (15c); Buenos Aires in 18th century (45c); First train, 1857 (55c); Sailing ship, 1767 (85c). CV=1.80 (0.45 each). SS CV=3.00.