Stephan,
From your photo it is clear that some major surgery has taken place in the past with your charging system. The Voltage Regulator (mounted just above the data plate) and the 3AW unit (mounted under the heater box) are clearly not connected to anything. Without knowing what alternator you now have, and how it is connected (including any connection to the warning lamp in the speedometer), it would only be speculation as to what is going on. It is pretty clear, however, that the original Lucas alternator is no longer in place.
-David