Got up to here, as of last night, but didn’t get time to post. I believe I came across the cause of my rendering issues, or at least 2 possible causes. Firstly there was some kind of issue with rendering a referenced object with an included texture. Secondly I had a PSD network on the postbox model from when I had started doing a quick texture for it. I had managed to have both that in the form of a lambert shader and a mia_materials_x_passes shader both on the postbox model. How that happened, I have absolutely no idea, although I suspect the issue lies with this, rather than the referenced object.
Anywho, most of the objects are now textured, I need to transfer attributes from the UV mapped window to all of the other windows and then I need to start spacing the UVs out and scaling them down to fit into the correct map size. The render isn’t great – it is just a quick Mental Ray render with physical sun and sky with FG GI included – I have just purchased these sIBLs though , which I look forward to using!