The best commercially marketed source for concentrated stocks in the US, Aromont, no longer carries their old French-made products. In Paris I have been trying to find something comparable. A few months ago at Detou (58, rue Tiquetonne, between Etienne Marcel cross street Montorguiel, 75002) I purchased two Belgian-manufactured Nestle concentrés that while better than anything I have found in the States are still inferior to the best Aromont used to carry.
As far as I recall Detou stocked no other brand of concentrés. Is there any shop in Paris that might have a bigger selection? What other brands are available?
By the way the Flemish names are respectively Gevogelteglace and Vleesglace.