it is pretty much that simple, as the bike has magneto ignition, then the dynamo and charging system really do nothing but power the lights and horn, so a convertion to 12v is really quite a good thing, also whilst at it you can convert to negative earth too to simplify it, this you will need to decide before buying a reg as they come in either 12v+ earth or 12v- earth, its a simple conversion and you can get the parts from srm, dave lindsley or any of a number of other classic bike suppliers. or, you could stick with 6v and just get a new voltage reg, and fit a better headlight bulb! my 53 beesa has still got 6v neg earth, but has a electronic reg, a halogen bulb, a led tail light a 6v gel battery and an electronic ignition conversion (expensive option!!) and works just fine on 6v, so the choice is yours, both work fine, it just depends what your budget is. if you need a new reg anyway, then going 12v means you need a set of 12v bulbs and a battery too, staying 6v means you just need a reg.
as for the little knowlege ive shared, well it was passed on freely to me by other folk who just wanted to help keep these old bikes on the road, and in the future, no doubt it will be passed on to others by yourselves, what goes around comes around as they say.
anyhow, before you spend money, you need to check that the bike is charging, you might have something as simple as a broken wire on your dynamo, or a set of dirty dynamo brushes!. so, have a read of these on the subject of dynamos and regs,
http://www.nanocontrols.co.uk/auto/v-reg2.htmhttp://www.srmclassicbikes.com/catalogue/index.php?target=categories&category_id=110http://www.davelindsley.co.uk/parts.htmlalso as a footnote, remember you have a limited amount of power even with a well set up dynamo, so try and save where you can , if youve 100w output, then a 60/55 headlight is going to use over half of that and that assmues that all your connections are perfect and have no resistance, hence i fitted a led tail and stop light which uses only about 1 watt, so dont start fitting heated grips and sppot lights !!!!!
