You need to add the entries for the images in the .dat file as instructed in the step-by-step guide, otherwise it won't compile. Also, the definition for the Connex South Central livery is spelled "Connex-South-Central". All livery definitions are at the bottom of the pakset simuconf.tab. Finally, we will also need separate graphics for the trailer, which are shared with the Class 317, as well as for the rear driving trailer, which you can make by rotating the front driving trailer and re-rendering.
To rotate the driving trailer, do as follows:
-Hide all layers except the one with the vehicle model by shift+clicking the layers so the layer manager looks like this:

-Press A to select the whole model. If you had something selected from before, press it twice.
-Go to Object > Transform and select "Origin to Geometry"
-Press Shift+S and select "Cursor to Selected"
-Press 7 to view the model from above
-Press R and type "180" to rotate.
-Show all layers by shift-clicking them in the layer manager shown above. Then you can render.
Oh, and it would save us some time if you added the entries to the latest version of the .dat file.