David Bean queries "...Ebay item 320359666881 is a cool-looking stem without any expander. I guess it must fasten with a clamp around the steerer. Any what/when comments?..."
That stem would be used with a headclip headset, with that style of headset being seen in earlier bikes. I'm not an expert on headset history, but my impression is that that style of headset diminished in use as the 1950s progressed, but practice may be country specific. See
http://www.hetchins.org/
..........
Peter Brueggeman
La Jolla California USA
4peebee(at)peterbrueggeman.com