Thanks for the comment Neil. I think you experienced this with your Steyr too : There is a lot you can get away with on German vehicles, if not proven by pictures then by educated reasoning.
Yet there is always a certain cominations of detail that must be right or it will keep haunting you.
usually nobody will notice this but in your mind you know : this wheel must have 6 instead of 5 holes, or, this engine hatch must be split in two etc...
On the other hand ; with every completely sought out and correct model we will be the experts on it and hopefully will be able to pass on that knowledge via this, or other forum.
(But after 10 year or so I usually have forgotten how I came to this or that detail....)