So I have finally completed the aerial mosaics that will now cover from the western station limits of Christchurch all the way to Opawa. As usual it has just proved easier to add the images for Linwood and Opawa to the Christchurch ones and so these extra steps have been completed along with Christchurch/Waltham.
In along with that I installed the new version of Gimp (2.10) and one of its features is the unified transform tool which makes it possible to combine the scale and rotation steps. In short, it is much easier to use than the scale tool because you can deform the image as well, which means in effect you can pretty well drag it to the exact proportions you need. I have been using a development edition of Gimp (2.9.7) for some time and this release of 2.10 improves on some issues as it is a production version of the software.
Here is the Gimp mosaic for Christchurch West-Linwood-Opawa which will now be split into several pieces to allow the production of the map tiles needed to be loaded into Qgis. Mapping will then resume.