Thanks for the Google Earth link, Jon.
I ahve also found this site (in English and German), which includes pictures of the railways line by line and a lot of interesting information in the captions:
Marcus Trains Site
Some of the locomotives are EMD G12 and G26 type (the latter built under license by Clyde Engineering in Australia), and purchased second hand from Western Australia Railways and Queensland Railways (3ft 6in Gauage). Also, as has already been mentioned, some NF210 type ex Newfoundland.
Don Newing
Derbyshire, UK