The third car here is still looking for an answer, so I guess I can leave it for a day or two, but if it's not solved by then this one will enter the Solved section.
Better (way) late than never.
The name I was looking for was 'Nagaro Technologies'.
"In 2000, Nogaro-Technologies bought Helem mark by Fior, and recovered many specific tools. Then in 2001, Nogaro-Technologies built, from the Spider F99 chassis, a new Helem prototype for French GT Championship (Muratet V6 3.0 litres engine, 280 bhp, sequential 5 gearbox)".
This is the only mention of the Fior in the article that relates to this car, and I really don't know for sure what is right and what's not, but I guess I stand by my earlier decision to give Paul a point for his answer too.