Renault 4 uses M10 x 125 thread on the wheel nuts, all Japanese cars have M12 x 150 or 125, so even if the taper fits you will not be able to screw them...
I think, there should be no problem to turn out a copy of the Gordini nuts. The nuts are blind on the end? How long is the hexagonal part? I have 4 waste alloy Alpine rims in my garage, however without nuts. There are the same nuts?
Here is my solution - I bought the nuts for Taiwanese fourwheel bike (picture 1), there is M10 x 1,25 and the taper 60°. They are quite cheap (1.88 EUR each). I turned the taper out for 45° (picture 2) and it looks quite good (picture 3),what do you mean?