Stephane Pennequin of the Nuts Museum has written this about my interesting chock:
“This exotic nut is a Coinceur Gigogne (Nest of Nut in French). It was marketed in France in 1979, by Laprade, a company that marketed a small line of climbing hardware. Laprade sponsored the outstanding French climber, René Desmaison.
The Coinceur Gigogne was invented by Jacques Paul Fournier and patented on August 3rd, 1979, (Patent FR 2410487).”