Here are 2 pictures to illustrate what was discussed last time.

A small scale QGIS map	The equivalent page of the NZ Railway and Tramway Atlas 4th Edition.

At a quick comparison there appear to be some geographical differences (apart from detail) between the QGIS sourced map and the Quail sourced map. Which leads me to believe that a map sourced from QGIS is going to be inherently more accurate. One of the more obvious examples is the placement of Greta station. On the Quail page at right, Greta is listed at 5 km north of Scargill, yet the distance appears to be similar from Scargill as the distance to Spye, which is 10 km south. There are also some less major differences obvious in the maps of the Waiau Branch.