Frank Krygowski wrote:

But again, thanks. (I'm hoping that on the bench, powering this with a
6VDC battery should be as valid as powering it with a dynamo.)

Not the AC-Eyc, RTFM.

But how about a new lamp and some real circuit?
http://tandem-fahren.de/Mitglieder/Framstag/LED/Wollmilchsau/