I seem to remember someone looking for one of these fitting clips recently, can't find the post. Anyway, hope this helps someone
BMW e9 CSi CSL Clutch Slave Cylinder Bracket - 21521102748 | eBay
NOTE - You are purchasing ONE slave cylinder bracket only. The slave cylinder is NOT included. Early clutch slave cylinder bracket. Remanufactured to high tolerances and zinc electroplated.
www.ebay.co.uk