Nice and heavy and cheap. A good combo. My only concern would be with IG or other acidic inks reacting with the brass or copper. Not sure if it would be a problem or not.
When I use a straight holder, I like to use 2 oz Nalgene bottles. I can screw them on tightly and carry them around safely, but can also see how much is in there and they don't react with the ink.
For use with an oblique holder, I've become a big fan of Dinky Dips in the wooden base. I've also used a shot glass for an emergency ink well and it worked great. I would imagine old baby food jars, the short, fat ones, would also work well if you have a lot of ink.
I'll take a look at the plumbing section of the hardware store now. They also have the end caps for plastic pipes that might work, but you'd have to improvise a cap.
And another hint, if you're looking to adhere one material (like a glass jar) to a heavier base of another material, since you can't weld glass or wood, I've become a big fan of Sugru. You can do amazing stuff with this moldable, sculptable silicon "glue."
https://sugru.com/ Ever since they started selling it in Target (large chain store in the US), I always have some around and use it for a million uses. Most recently I took a section of an old glass stir rod, and molded a small bulb at the end containing a tiny rare-earth magnet using sugru. I use this to retrieve steel nibs that have fallen into my ink bottle. It's only happened a couple of times, but it's a real pain when it does.
I've also used Sugru to creat a new "seal" for the inside of the cap of an old Sheaffer ink bottle, the one with the built-in filling "shelf." Which, by the way, is also a great bottle to use for dip pens. The built-in shelf works quite well for even oblique holders. If you can find one of those they work well. Unfortunately, they haven't made those bottles since about the '80's. But they were made from the 30's, so there are still quite a few around.
No connection to Sugru, just a huge fan.