John,After reading your post which included a name of the rail type (thanks!) I searched around a bit for some other info. Pretty fascinating stuff! Peco even produces track in this configuration and I'm sure others do as well.
Yes, I did notice the various new and used looking areas on the loco. The front right deck edge looks more paintless than the left side probably from access to the smoke box? The cow catcher or the UK equivalent has all it's paint so I guess they don't use it for a step up.
If it were shiny all over then you picture would probably have had loads of sunlight bouncing back at the film.
Dean