DS21 Distributor, S.E.V. Machal or Ducellier

[rustedtight]

Hello, I am working on 1970 and I too can't belive that there are no postings. It is a Citroen DS21, very similar to Jay Leno's car in his collection. I currently have an S.E.V. Machal distributor in the engine. I have ordered a cap and rotor for the car and find they do not fit. I was told it should have a Ducellier distributor. The offset drive shaft to the camshaft is very similar to VW and I read that the Company is a German owned. Car was exported to Canada and found its way here. It is not my car but I am helping this poor fella who loves this automobile and it is very different from any thing I have worked on.
Does any one have any idea if there is swappable replacement or a know the correct Cap and Rotor for this Distributor?