Hi Tim!
Despite the time I do not post any message here from, I enter the site often to see what news are here.
I've read your post and I must say you that German manufacturer "Paulmann" has in his catalog an oscillating candle lamp very similar to such you described. These has a coil fixed into the candle body and a magnet attached to the lower side of the "flame" part -the lamp itself mounted on a pendulum suspension-. When the AC passes through the coil the alternating field created by this, reacts with the nearly placed moving magnet piece, making the whole lamp some chaotically oscillating in an "open flame" fashion.
The two prongs emerging from both opposite sides of the lamp, which are directly connected to the lead-in wires, allows the current to reach the lamp through the suspension system itself without any noticeable disturb to lamp swinging.
As these lamps are designed for European market, they are fitted with E14 cap and rated for 230-240 V / 50 Hz, so, they can be OK for British use.
The main drawback is that these lamps are only 3 watts, so, they spreads a low light level. I've seen one of these in action some years ago, and I can say you that is a very eye-catching effect.
Please tell your friend that visit this link for more info:
http://www.paulmann.de/index.php?Land_ID=1&Sprache_ID=2&1Menu_ID=84&Anwendung_ID=22&EcatAction=Artikel&Katalog=2460&Kapitel=2460&Artikel=53300&Sprache=EN#2460Regards,
M. Gonz?lez.