Your nice Raleigh Competition needs Huret Jubilee derailluer. Now, before you spend your hard earned treasure for one, be aware that there are different models of these, short and long cage, and more importantly, some are configured for Campagnolo ends or Huret ends as you have. Allegedly there is another type I have been told but I have not seen it. Huret Jubilees are fetching more money of late, I bought a complete set a while back, levers, cable guides and mechanisms for $90. plus shipping two years ago, an outrageous deal at today's prices.
Here is a case where parting out a bike yeilds much bigger revenue than whole.