[DennisAN]

The design of the IMS flange was changed due to oil leakage problems. The old design used a rubber O-ring. The replacement new design used a rectangular 3-rib rubber gasket that doesn't leak. It is not unexpected that it would get changed.

BUT you are lucky. You have the paperwork....check the flange number. You should be able to determine whether you have the dual-row IMSB (likely) or the single-row IMSB (random in 2000) by the part number. Download the free PET from the Porsche site (parts breakdown).