What this exercise has demonstrated is how easy it is to get roof details wrong. From the side shots you get the impression that there is a single row of ventilators, and one of the drawings I have suggests that too. However, thanks to that loan to Western Australia and the fact there appears to be a footbridge at Perth station I now have a couple of views that clearly show a double row. The scan I have of the QR stock book doesn't show that that well, only when I was able to compare things did I realise that what I thought were light fittings on the interior plan matched the positions of the ventilators.
These carriages do appear to have been much shinier in their Australian days than they are now. I'm not at the painting stage yet, but I suspect I will actually be painting them a grubby grey