I sourced a wasserboxer distributor (Thanks again Andreas) and armed with all the parts (ignition module, Volkspares harness, new high voltage coil) I thought I'd do a quick distributor swop - NOT!!!
With everything connected, basic timing set, it was time for the BIG EVENT.
The engine swings and....... Nothing

Now the doubt set in.
There are only three wires and two pre-wired plugs to connect - black is positive. green is negative, brown is earth - double check

Still, there is no spark at the distributor cap.
Check the green wire with the engine turning - no pulsing signal
Take out the distributor and check for a signal from the hall sensor - Checks O.K.
Check for the same signal at the control module - It's still there.
Check on the green wire to the coil - no signal - Damn duff control module.
Fortunately, Goldwagen are not too far away and Andrè volunteers to go and get a replacement - and sommer the special wire from the coil to the distributor (the HT pin on the coil is not compatible with the standard HT lead)
With the new parts fitted and the distributor replaced, its time for the SECOND BIG EVENT.
This time all expectations are met and Petrus starts fist time. With the ignition timing set with the strobe light, he settles into a contented idle.
The idle is smooth and it revs clean, so I expect lots of hassle free kilos from this conversion