Understand all that worthy ambition Chaz.
But there are Big Buts . . .
Point One:
a)You don't want and can't have a rectifier with a dynamo - you're producing dc already because that's what dynamos do, thanks to the commutator, which is a mechanical rectifier.
b) Rectifiers go with alternators, which don't have commutators and produce AC which needs converting because there's no such thing as an AC battery even if sparks and lights can run off it.
c) You want a dynamo regulator and cut out.
d) The simple fact that you're negative earth is not a reason for putting a Japanese alternator system part in there. It won't work, I promise. A dynamo regulator manages the dynamo's output (D) by controlling the dynamo's field coil input (F). Dynamos are very elegant devices in that they serve up power according to demand rather than according to simple rate of rotation, so the regulation has to be designed to match output to electrical demand. Totally different principle from an alternator, whose output, unregulated, would be solely dictated by rpm. The means of regulation in an ac regulator are completely different from a dynamo's.
Point Two: the idea of getting better lights when the dynamo's going to be overloaded because of ignition loads doesn't stack up.
You have to start from first principles.
Your DC system produces a nominal 60 watt maximum safe output.
That's 10 amps at 6 volt, 5 amps at 12. Yes, fewer amps with higher voltage because watts equals volts times amps.
Your Rita/Boyer/what the hell? ignition option will consume 2 amps at least at 12v.
That's 40% of the dynamo's current rating (amps) and will leave you with a mere 3 amps or 36 watts of power, at full 'regulated' rpm, for everything else.
The tail lamp and speedo take maybe 8 of them, leaving 28.
If the sidelight up front stays on with the headlamp, that's another 5W-odd gone, so 23 left.
(LEDs can reduce this a bit, but not enough.)
At engine rpm between about 1000 ('cut-in' rpm) and below about 1800 ('regulating' rpm) the dynamo is feeding the whole output from D into the field coil, F, unregulated.
Under full load, ie lights on and ignition on, that's a lot of load on a small generator.
Above about 1800rpm the regulator, if you had one, would manage the field input to prevent a meltdown in the armature, but it wouldn't maintain system voltage because the loads are too high for the dynamo's capacity.
The battery would gradually lose charge as it would be making up the difference.
The 'big question' here is not how to pick from some mix and match menu of attractive-looking options regardless of what you've got, but is whether the basic electrical system on your machine can properly support what you want to do. It can't, it really can't.
You need a good dynamo, a decent voltage regulator and cut-out, whether mechanical or solid state and I favour the latter, and, for choice, a magneto (or other independent spark generator). Or, you need an Alton alternator with its own built-in regulator, if you want to have powerful lights plus electronic ignition. 12v on its own is no magic solution, nor is a solid state regulator, and least of all is electronic ignition. Which is not, IMHO, likely to do anything useful for a '56 A apart from flatten the battery and maybe fry the dynamo.
