Sorry Pal, I missed your replies.
about #4, one of them had a VW 1600, the others Ford V4 2 litre, there were made only 13 moulds (I don't know how many were completed...) and the builder was from South Africa.
about #1, he was listed as a car manufacturer in many sources (a couple of well known encyclopedias, or a small guide of French cars...) but the years may differ from source to source. All of them report more than 25 years.