The Anglepoise originally had flat 3 flex (no sheath) and this seems best for fitting into a square tube. The 0.5 sq. mm. that I used has an intermittent break at one of the 'elbows' and, as it's such a faff to get in, I'd like something that lasts longer.
I can't find any that's like the old type, mainly because the vas majority of hits for flex come up with cable.
Any ideas for a source, please - or an alternative form of flex?