Arteleuce Floor Lamp Component  

Machine Shop
It would be relatively easy for anyone with a machine lathe to turn a piece of aluminium stock into something that is very close to that end cap. Make a quick drawing, measure the threads, and look in the yellow pages for a local machine shop. You might even find someone willing to do it for a case of beer.

I have attempted to have...
I have attempted to have pieces fabricated in the past & in most cases there is a set-up fee & they require a minimum order of several pieces before they will go into production,most companies are not willing to do small quantities or "one offs".

Try Mark McDonald...He has...
Try Mark McDonald...He has made a similar lamp that uses these end caps. I purchased two from him several years ago for my lamp and they were a perfect match. I'm assuming he will still sell them.
OK, so I just looked at his website and didn't see the lamps and also can't find the thin edge cabinets that he was reproducing...Maybe I'm thinking of someone else?

You're thinking of
Daniel Donnelly and his "Donaluce" lamp.

Tis a beauty!
I'd love to have one of those! Probably not cheap,but much less expensive than the real thing.

Only slightly less expensive
unless you shop for the real thing on Ebay, in which case you're correct.

yes, thank you
Fastfwd...I've also purchased Nelson thin edge pulls from him, new and old.

very simple 20 minute job...
very simple 20 minute job for someone skilled with a lathe.