Recently I have developed a 2 foot "tuning fork" fiddle-yard for this layout to better enable shunting and to bring passenger rail-cars and auto-coach on and off scene. The top of the fiddle-yard may be removed for operations from the front or replaced for exhibition operation from behind the layout:
Just looking at the last shot of 079, painted date shows December '17. That's a good few months getting other things done, was she waiting on new refurb bogies. I know 082 spent months on temp bogies during overhaul.
To me I always find it odd that the livery application is not left till last after all other work is complete.
The CVR stuff certainly appears to be a mix. CIE narrow gauge wagons ended up in a deplorable state - thus, rust.
A few CDRJC wagons appear to have had some black ironwork, but others all grey.
When jhb171Senior visited the CVR in 1937, nothing black was to be seen on any wagon ironwork - at least, not by him. However, I have certainly seen photos showing black on some stock at least, so it is likely that the policy changed at some stage.
As Mayner says, however, on the NCC, UTA, GNR, GSR and CIE, ironwork was never picked out in black. Nor on the BCDR. Exception: the BCDR had eight private owner wagons belonging to C Ritchie. Initially at least, these had black ironwork. The East Downshire wagons also look as if they may have had black ironwork, but photographs are inconclusive given weathering and rust.
In reality, black and white photos are highly unreliable for colour shades - very obviously!!
The silverfox Hunslet can be bought as ready to run ,or finished body ready to pop onto a bachmann/hornby class 20, or as a body kit with all paints transfers etc included. As I already had two class 20s I went for the middle option they run well and look well too. The mk2 coaches are handy enough to paint in the blue/grey to match. I will check out what paint I used for you. Look up silverfox models/NIR locos. Ian