They were mainly sold by France Telecom, the historic french phone company, so they could be found on the rare computer swaps,or on our local "Craig-style-list" named LeBonCoin:
Here's one I just found, for around twenty bucks: http://www.leboncoin.fr/informatique/773121220.htm
Just remember that there was the original 2400bds AppleDjinn (with a serial cable coming from back of enclosure and the j11 connector on the side), and the 14400Bds AppleDjinnPro (with female serial and RJ11 connectors on the back); the power supplies also differ in voltage and connector... Good luck !