source of cheap narrow thin tube?

[mklotz]

Is there any chance you could use shielded wire? Normally it has only one conductor but multi-conductor may exist.

Two foot lengths of hobby tubing are unlikely; I've never seen lengths longer than one foot. However, telescoping brass tubing is commonly available in the hobby market. Soldering two pieces together to obtain the required length would be easy and there would be negligible added mass.

A quick Google for "telescoping brass tubing" yielded this hit...

https://componentsupplycompany.com/p...-tubing-sw.php

which, in addition to the 1 ft lengths, shows 3 ft lengths.

If they don't ship to Oz, look for 1 ft telescoping lengths in the local hobby shops and consider the soldering suggestion.

BTW, "guage" is a small town in Kentucky, correct spelling is "gauge"