The box sizes 14,7 x 12,7cm and the maps only 13,0 x 10,0cm. There are 24 maps showing the two hemispheres, continents and countries in the 1840s.
An interesting map is the one of the 27 Northamerican Free States (including Texas as the newest one in 1845). So we can narrow the period of the maps down to 1845-1850.
Unfortunately there is missing the upper piece of the Turkish Empire. But it's okay for a game of the middle of the 19th century.