For all those who do no know it. There is a online parts catalog from BMW Germany which covers all historic cars, there are lists of parts which are specially made etc.
http://www.bmw.com/generic/com_04/de...rts_2_1_1.html

The only problem is that it is in German only from BMW. You have to register first and get a password.
I have registered and have now access, very good info.