Yes Vic, they're "mesh" braided wire sheath over the ignition lead itself, rather like a "Aeroquip" hose.
My pic is the P-47 at Duxford, before it was hung up from the ceiling (Grrr !!!), and looking closely at another, full size image of it, the leads appear to be a faded copper colour, sort of a silvery/gold/brown shade.
I've checked other pics In my references, and they all appear to be the coppery shade, with a few exceptions where they're silver-grey.
If you opt for the copper shade, then I find that a drop or two of a brown shade, such as Dark Earth, added to silv er, replicates this quite well.