I think that the earlier Peugeots had a smaller small chainring and that type of FD doesn't handle those well. They work fine if there's not too much difference.

None of my Simplex FD's of that type allow the rotational adjustment that John mentions. The flat spot in the rod that the set screw runs up againt sets the angle. Also, I push the shifter all the way forward and remove any excess slack from the cable before doing any adjustments

Your rear derailer is not the common Prestige, but the Criterium model. I still have the original from my '74 PX10 and it would still work if I gave it some new pulleys. The front is a Prestige.