I've seen the crack you mentioned many times before and also the locks with the snapped off piece stuck there. I would have a go at a standard key and just see if it works and stays in the lock correctly. A botch job is to remove the metal key from the plastic handle and super glue the plastic bit to the steering column as close to the lock as possible, or find a way of taping the reciever ring inside the column trim together. Then just use standard keys but this will stop the NATs from working.
Just a bit of info regarding the keys.
The type of blank is known as an "X", this is the same profile of metal for the red dot type and standard.
The key has 8 cuts of various depths, these are symetrical along either edge of the key.
There are 4 depth's known as 1,2,3 & 4. 4 being the deepest which should only just reach the ridge on the key blank. Number 1 depth only shaves a little off the blank.
The profile of the combined cuts should be a pronounced step shape following the cuts, there should not be any curves what so ever. Any slicght jagged pieces between cuts should be so slight they can be removed with a wire brush.
If the key supplier uses a cutter that follows your old key forget it!!!! The only chance you have is for the supplier to cut from a key number so that they get the correct 8 seperate depths. The key number used to be on a white sticker in the glove box. Failing that take your log book to a dealer and they should be able to look the number up on the computer system for you, may be get a standard blank cut at the same time. Once you have a working standard key then a supplier who follows the profile will be able to cut a key for you. I would advise that you always have two working keys without cracks. A replacement set of locks will cost a lot more than a second key.
Hope this helps.
Jim T
PS I guess this makes me sound really sad :roll: