[Rusty]

When working in the electrical trade 20 years ago I threw hundreds of split conduit fittings away when rewiring houses. I assume as Australia followed England that you Poms whould have the same stuff we did which I am sure is identical to the wiring conduit in carriers. Try ringing electrical wholesalers and ask which one of their sparkie customers is a house rewire expert. You may strike it lucky that someone is having old cotton canvas cable in conduit removed. Failing that get up in roofs of friends houses that 50 plus years old that have been rewired often the sparkie leaves the old stuff in place because it more cost to pull it out.

Take extreme care doing this some pipes may hold live wires or still have an earth connection running through the pipe structure.