The ignition is something I've never come across before, it appears to be a distributor rather than a maggy.
Firko, That exact unit was still used upto and on early round case road and enduro Squaries(the only ignition case that it will fit into).
The heart of that unit is a DC generator(complete with armature and commutator).
The bobbin in the bottom left corner, is the adjustable voltage regulator.(you will be able to trace one of the wires back to a carbon generator brush, the other brush will be to earth).
The coil situated at top left is the high voltage ignition coil, hence the casting relief on the rear RH lower square barrel fins for the routing of the high tension lead up the rear of the cylinder.
These systems were battery pionts ignition which produced a solid spark at kick start revs. The rusty unit in the middle is equipped with two centifical weights and is actually an automatic mechanical ignition advance. It is NOT to be thought of as solely an ignition advance, but rather a unit that retards ignition timing at rest and kicker RPM so these engines could be started without fear of kickback.
They were a great road/enduro system In their day. That is, if they were kept ventilated, dry and maintained.