As the change in wiring harness for 1999 to fiber optic it seems the trunk lock assembly is not compatible with any earlier ones. Unfortunately my lock tumbler had to be destroyed to retrieve the key inside in the middle of nowhere. (I curse the engineer who though it was a good idea to have the car lock itself after a period of time if a door is not opened ) Since the dealer says no longer available is there any source for parts no longer stocked by MZB itself.

 

Able to find all the locks and key for trunk on ebay so solves this issue.