This is sort-of off-topic, but Helmut Uttenthaler, who went by rail from Vienna to Pyongyang in 2008, returned to North Korea last year on a railfan-oriented guided tour and has started to write up the trip.

Part 1: Introduction

Part 2: Vienna - Beijing - Dandong

Part 3: "our special train"

There are lots of interesting photos, ranging from decrepid freight wagons to a mysterious unnumbered carriage in the charter train, which has tinted windows and might have been taken from Kim Jong Il's private train.