As stated above, index housing is wound in a long shallow spiral (almost linear) and depends on the strength of the plastic to not buckle entirely, so it's not suited to braking. Brake housing is wound like a collapsed spring, and so is all steel on steel and cannot buckle under load.
If it helps, I have some very nice NOS Casiraghi (made in Italy) Brake cable kits (2 lined cables including inner wires) in pink or Lilac.. I could sell either for $15.00 including postage within the USA. PM me if interested.
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