Decoding keys / dimple positions
1. Keys4classics are the expert - the only people I have found (incl. BMWNA) that understand old keys. Highly recommended.
2. When I bought my car, I had a small Pebra ignition key and a second black topped key that opened the doors and trunk. BMW would only make a copy of the larger black key and just told me flat that they could not do the igniton key without explanation. I found this rather odd.
3. After many deadends, sent jpegs of keys to Keys4classics in Oz. One email later I learned that the problem was that the two keys came from different groups - i.e. my ignition key was in fact, a 'valet key', and did not match the others indicating my car had a different ignition cylinder than with the original car. They explained that the master key for a CSi has seven dimple positions, and the valet key 6, so the valet had no access to the trunk or locked compartments. The first six dimples on the ignition did not match the first six on the car master, so they must be from different locksets.
4. They are making me two new ignition keys, should be here in a week. I am on the hunt for a complete set of matched lock cylinders and keys that match with the master and valet key.
Hope this helps anyone with a key mystery.