Sturmey Archer AG Dyno hub lights

[combrinck4]

Good day all,

Does anyone have any experience with Sturmey Archer AG dyno hubs?

I recently got an old English, 3 speed bike that I'm busy restoring. I managed to get the hub open, and got the seized magnet and router loose and turning again.
Anyway, the hub is turning as it should, changing gears as it should and putting 6V out as it should. Unfortunately, I received the bike with a broken/shattered rear bulb. 
Does anyone know what bulb I should replace it with? I couldn't find any information on what the original looked like. That's why I'm asking on this forum.

Photo borrowed from: https://deadrats.co.uk/2017/05/25/1967-elswick-hopper-safeway/olympus-digital-camera-3921/