That's why I said tin and copper are easier. There were locations with native copper deposits, much like finding gold in streams. Copper is easier to work, tin is pretty easy relatively speaking, and the two give you bronze, which allows proper tools. That's part of why it took about 2000 years after bronze before we had iron. The guy from Primitive Technology is working from a very poor ore source (and is actually doing trial and error). That said, I doubt you could get much more than the idea of iron accepted by a Neolithic culture in a lifetime.
Sure, I've built houses using modern tools, but I'm also aware of the techniques used in older wood buildings. I could be an adequate apprentice for the first house I built, and could build a second on my own.
I didn't say gun powder, I said black powder. It's far simpler and safer. I made some before I was a teenager. The hardest part is finding saltwater and the only tool you need is a mortar and pestle. If they didn't exist by 10000 BC, then I could "invent" that, too.