AndyTom
There's some interesting stuff here:
www.r4-4l.com/tous-les-modeles-de-4l/4l-sinpar-4x4/
There's some good information on www.La4ldeSylvie.fr - just do a search for 'Sinpar'.
There's also an interesting renovation here:
www.retro-meca.com (if this link doesn't work, just Google 'Restauration f4 Sinpar', and you'll find it).
(To get a translation, right click on the article, then 'Translate to English')