IT seems that only the PN versions are the only ones close to correct.
To be fair, John was showing the original painted sample of the SRA 81 class with the incorrect "door" at one end (really a small access hatch replacing a fixed porthole) last year. It had the correct single engine room door. He instructed the factory in China to correct this hatch error. What appears to have happened is that the factory then used the later version with the double engine room doors for this model. So instead of making his correction, they made an additional error.
As far as I know there are no consistent differences between the Freight Corp blue body and the PN blue body in the prototype. The inset steps have been removed from a number of 81 class and this certainly is a feature of PN units but since I don't know when it happened, probably appeared on a number of FC units.
As I've said earlier, the PN livery only represents the first batch of four batches of repaints, so maybe a quarter of current PN 81 class, particularly the blue cab roof. I was so used to seeing yellow cab roofs I had to check that there were any blue cab roofs.
The FC version looks quite good, although I'm told the separation between blue and yellow is too high, but this appears to be the same problem as the same break on the PN version. So there is really no difference in accuracy.
The livery errors are a mistake by Austrains. The incorrect body features are a factory error.
The body changes on the G and BL are much more subtle and the livery break points are more easily located by body features, with less opportunity for error. But has anyone checked for the absence or presence of the inset steps which certainly changed pretty early on. I think by the time Powerline produced the G2 their G1 model was incorrect because the steps changed.