260SE's. A lot in Asia.

Engine is a M103. Engine number is down on the side of the engine down under and just to the rear of the alternator.
You will probably need to clean the area before you use it.

or

get the VIN number, go to the Russian club site and the info given will also give you the engine number and all the details re the car.

http://old.mbclub.ru/mb/vin/?lng=eng

If that is an image of your car - it looks a pretty clean example. - and that is a M103 engine.