Sorry I'm late to this party!
I did something similar with my 1946 Hetchins when I 'restored' it in 2014.
It's got a SA Dynohub and original Sturmey Chrome shelled front & rear lights - but the gubbins are LED.
The website with all you need to know is at
http://www.reflectalite.com/For the LED lights to work correctly with a Dynohub then you'll need a 'regulator' from them - I've just checked and I've got a GENX2 fitted across the Dynohub terminals. (see
http://www.reflectalite.com/regulatorpage.html )
I bought the correct fitting 'bulbs' for my lights from them as well and the system has worked well for the last 6 years (albeit with limited use).
It's not a cheap route, even back then I spent £28 on regulator and two LEDs.
I used new wiring, the original would have been white/cream which would have looked shite even if I could have found some.
The correct fittings to the hub are 'horseshoe' style crimped & soldered ends.
As regards the 'battery box' - this was a common fitting on utility bikes (and possibly some tourers) had a cylinder on the seat tube to contain three D cells that would act as a back-up for when the generator wasn't running. All the Sturmey Archer front lights that I've come across have a three position switch that allows for this to be switched in (possibly) automatically. The wiring to make this work is something that has always defeated me - indeed the wiring of the front lamp
without the battery back up is bizarre enough (IMO). These original battery cases do come up on eBay occasionally at silly money - if you were so inclined I suggest they're easy to bodge. It wasn't a fitment on my bike originally so I've never bothered, but more to the point I like having the security of a second light source.