Here's one website that makes a point of dispelling the "naked savage" idea of the iron-age Celtic warriors, who routinely would wear chainmail armor: http://www.academia.edu/3891226/Celtic_Chainmail
Everything I've read shows that they had the technology for butted mail but may not have figured out riveting yet. Known examples of butted mail among the Celts goes back to at least 300BC (per the article at least).
I wish I could do riveted mail, but it takes a lot of resources and tools that I don't have. Riveted mail means having to flatten out the ends of the rings or stamp them out of sheet metal as flat rings, punch a hole in both ends, thread a wire through it, and rivet the wire down or somehow connect it back to itself. It would be much stronger, but I'm working out of a living room with no real shop to speak of, so you can see how riveting might be a little beyond my means right now.
Back to the main topic, I would love as many resources as I can get, I'm not a technique-purist in the sense that if I want to make a viking-age item it has to be with viking-age technology, for example, I plan on finding what works best for me and adapting it to make whatever it is that I need, and starting with a good (but cheap) anvil was where I was going to start.