looking really closely at the photo, that sure looks like a candle inside the enclosure. I don't know if you realized that or not, but might help you with search terms... posted by Bohemia Mountain at 6:48 PM on February 9, 2011
Vintage versions are available on ebay (example), search for "bicycle lamp candle". There are other versions that use carbide rather than wax candles. Carbide is extremely bright so it would be more useful than a was candle. posted by ChrisHartley at 6:49 PM on February 9, 2011
The book Early Vehicle Lighting By Peter W. Card is available on Google Books and includes a section on bicycle candle lamps. They were apparently somewhat popular in the 1860s, 1890s, 1900s and 1930s. The book mentions several brand names that may help you search. The image you linked does seem to be a modern reproduction but I haven't found anyone who makes them yet. posted by ChrisHartley at 7:06 PM on February 9, 2011
posted by Bohemia Mountain at 6:48 PM on February 9, 2011