I'm pretty sure the 95 had an analog port under the hood for pulling codes / data directly from the engine computer and a sub computer that translated then sent codes to the under dash OBD 2 connector.

This does not give exact model / year info, but will give you come info. The 38 pin connector is under what looks like an oil cap on a black computer case. this case will be on the passenger side of the car ( some cars have the cap on the drivers side )

MBCluster.com Mercedes W140 Instrument Cluster Repair Homepage

I do recall some CA emission testing info that early OBD2 MB were difficult to pull information from.

Regardless, there are a few different communication standards, not sure what you will have. It is doubtful that any scan tool will have the MB code meanings pre loaded so you will likely need a MB manual.