Spanninga makes an inexpensive black bottle dynamo that I'd like to try, but I don't have a bike that needs one at the moment. Buy the mounting bracket and this, and you're lit up for little investment. Not very vintage looking, though.

I removed a cool aluminum, German bottle dynamo, chrome headlight and taillight from the Puch touring bike I'm restoring for a friend. It had hung in the garage for years, but lit right up rolling down the sidewalk. I've yet to ask her if she wants me to reinstall it.