One of these?
Sturmey-Archer Heritage :: History
or these?
Sturmey-Archer Heritage :: History
Either way, I think the lights should work without batteries installed. You may need to try all positions of the headlight switch. Or you could try installing 3 C cells.
This company sells parts for LED conversions:
REFLECTALITE LIGHT BULB FINDER I have used their "Nicelite" replacement bulbs for battery lamps and seen a big improvement, but not the dynamo stuff. I made my own for that.