I hear what you are saying about ECAS not answering emails. Fortunately, being an old bloke, I remember how we used to communicate before emails - the telephone (which is a bit more expensive when phoning from Australia). I have had a lot of dealings with Roy over the last two years when building Daffy Duck. He accepts orders and dispatches them promptly unless they are out of stock with a particular part. He will gladly answer your query whilst on the phone. His website is very good for English only speakers, as he has a photo and a description and often a handy comment - like the yellow coil having the same resistence as the Ducelier and being compatible with 123). I also have Club Cassis catalogue and Der Franzose catalogue, but have difficulty with translating the Club Cassis (I can understand a French letter, but not the language). I also dealt a lot with Viking when he lived in Perth, Western Australia as he was the only 2CV parts outlet in Australia. His website was and still is in English and has photos.

I accept that the yellow coil HT lead plug ends are a tight fit. Since I replace my spark plugs each 5000 kms (along with the oil and oil filter), the plug tips are not corroded, so the HT leads are still OK. If/when they need replacing, I would go for the same ones. I am sure that Roy will be able to source replacements and if there is a demand, he will add them as a separate item to the website.

Daffy Duck

I think it doesn't make any differents (black or brown) as long as your sparkplugs and leads are in good condition, as long as you have a spark everything is ok. But on a cold winter day with a weak battery and bad spark plugs the brown one gives you still a spark (this only works with computer added spark read 123 or dg or cassis) and a black maybe not.
Fuel consumtion must be equal as long you have a decent spark.
So for me a black one works fine.
My own car runs on a free programmeable ecu and yes it runs on a black coil.

See my car running aon LPG injection here:
http://www.youtube.com/watch?v=_oEY5LSovEI