If it's that original, with it's 3 brush dynamo etc then it looks like you have an unmolested motorcycle from the early thirties. If I had it I wouldn't modernise it at all, just try and keep it as is. There's not many left like that! Some sources quote only 1100 made. After all it was in the middle of the depression era.
It's quite simple If you want to convert it? Which I have done on a couple of Miller dynamos. You remove the obvious third brush and it's holder (if you want) and the cutout (if fitted) which is often mounted to the side of the dynamo. There should be two wires! one from the field winding 'F' and one from one of the two brushes 'D'. These are wired to the corresponding terminals on the regulator F.A.D.E. A= ammeter E= earth.
Some useful stuff here too. http://www.dynamoregulatorconversions.com/2-brush-dynamo-conversions.php
