That is a standard wire-wrapping wire. I used lots of it when prototyping circuit boards. I have oodles of it around my workshop, but I find it of limited use for 1:25 scale cars. While the 30AWG wire itself is 0.010" in diameter, the overall diameter (with insulation) is around 0.016" which is too thick for factory-stock ignition wire. It is acceptable for some heavy duty racing wires, but I don't build many of those models.
Also isn't beading wire simply enameled wire? The enamel is translucent so the wire looks like it has metallic color (not a solid opaque silicone-like color). No go for me.
insulated wire extracted from old electronic devices is a good idea, but again, too thick for ignition wire. But it makes for good hoses.