Instructions to get a 45cmx90cm (depth x width) World Map as show in the picture 1 and 2:

Stl files from Africa needs to be scaled 0.7 on x and y only. Madagascar needs to be scaled 0.5 on x and y only
Stl files from Europe needs to be scaled 0.5 on x and y only.
Stl files from Russia (Part1 and 2) needs to be scaled 0.5 on x and y only.

All other files that I did not mention here are already on the right scale.