Hi Harv,
Picture hanging wire is quite effective and is what a lot of AM producers supply at least for their Shermans.
If you have a plastic wire part you could heat it in some hot water and gently bend it into the shape you want. (takes a few goes to get the shape you want). The trouble with using a naked flame is that the plastic either catches fire or softens too much. :-) :-)
You can use different thicknesses of string and coat them with PVA (White) glue to stiffen them up and then paint them. If you wet the string at any time it will become flexible again and you can shape your cable accordingly.
When you have the size and length you want cut off and drill out the ends of the fittings and glue the lot together.
I've tried various methods with varing degrees of success and failure. A bit of experimentation will reveal the method you prefer most.
Hope this gives you a few ideas.
Cheers
Al