Here is me idea on the steel coils.
More a proof of concept than a solution!
I've stripped some multi strand wire (I got from a DCC kit, it's used for track droppers) and unwound the strands. Simply wrapped about 7 strands- each about 20cm - around a paintbrush.
I've made a mess of it as its a quick lets see, but If you made a proper tool to do this, I reckon you could get some excellent results! I tried to put the brace wire through the center and rethread onto the brush, but this distorted it somewhat.
If you could make a dowel with groves along its length and place the brace wire in before wrapping the coils, I think you'll get the neat effect of the real thing. Prob want a jig to hold the dowel while you wrap the coils tigher with both hands. A bit of weathering down n I think the scale would be just right! The brace wires can be wrapped accross the coils on the dowel, then soldered at one end or in the center to hold it all together.
It's a bit of an effort for such a smal item, but I'll throw the idea out there!
edit: for scale reference,
Might also take someone with a little more finese!