You can substitute almost any older bottom-pull clamp-mounted front derailleur, although a few may require a thin shim for your 28.0mm seat tube's outer diameter. (The rest of the world used 28.6mm.) If your new front derailleur lacks a cable housing stop, just thread the housing under the bottom bracket shell and leave the end nearest the derailleur "floating." Great choices for your Peugeot are SunTour and Shimano -- I have a Shimano Titlist on my UO-8, and I had a 600 on my PKN-10. That original Simplex front derailleur is indeed cr@p. (I shouldn't talk, since I have its Campagnolo Gran Sport equivalent on Capo #2, but at least the Campagnolo's cage moves slightly upward as it moves outward, so that it tracks half-step gearing very nicely.)