I was in Paris recently and saw an interesting Mercier frame. It was a model "Formule 1 Performant". It was a mixte (with a single top tube) that appeared to be fillet-brazed. It had Vitus tubing and very interesting Shimano components: The shifters were mounted to a tab that was brazed to the down tube, and the brakes were center-pull, but cam operated. The seat tube, I think, was ovalized so that the seatpost itself was ovalized as well. Sorry, no pics, but does anyone know anything about this frame?

Thanks