Must have been some Reno Club thing on at the time - cant imagine why else you'd see a Reno 4 at a track and those 5s are awesome.
Respect to the little 205, isnt it the electrics that fail on french cars though? Yours being stripped wont suffer these problems - you've even cured the 205s leaky roof issue!
Great pics. Really nice to see all those cars from totally different eras mixing it up.