Earlier this year I contacted Leen APK to have a 123 distributor repaired and they asked for the date that is on the side of it. Mine had no date, therefore an early one and their reply was that there are no parts available. Re the Powernition units-they are no longer being made. There is also a company in the Netherlands called CSI-ignition and their units look very similar to the Powernition one but they do not make Citroen units anymore.
Dennis Hewitt