You can find awesome images of the two bimetallic types at World Bimetallic Coin News.
You can order these coins from Murtaza Karimjee (firstname.lastname@example.org) at his web page africanbanknotes.blogspot.com or from his eBay site.
My own scan of the 10 piastres:
The 20 piastres:
And the 50 piastres:
(news and images from Aidan Work, Pabitra Saha, Niels van Schendel and myself)