I feel that I should end the agony - and, as he evidently knew the identity of this aeroplane, impose on treadigraph the obligation to post the next mystery!
For those who didn't get the clues, Claude (
Clawed) Piel (
Appeal) named the majority of his aeroplane designs after
precious and semi-precious
stones (the exceptions being the Pinocchio and the Donald). That illustrated is the Piel CP.150 Onyx.
I'm surprised that Asturias56 didn't make the connection as he was so close. Had he translated his list into French, I'm sure that the penny would have dropped when he saw the Piel Rubis (ML.125), Emeraude (CP.30), Saphir (CP.1320) and Diamant (CP.60) listed before him - aeroplanes much more interesting than the Cessna 152!