Those numbers are chassis numbers. Your car is a W201. Basicly these numbers are Mercedes prodution numbers. My car is a W116 chassis, but wqith a 3.0 5 cyl. diesel. In the same car/chassis they had a 2.8 straight six, a 4.5 liter v-8 and a 6.9 liter v-8. Since "back in the day", Mercedes named their cars after engine displacement, there were 4 different "models" for the same car/chassis. For the W116 chassis there was the 280SE, 300SD, 450SEL and the infamous 6.9. For your chassis, Mercedes had the 2.3 4 cyl., 2.5 diesel (in Europe) and the 2.6 straight six. Again they were physically the same car but with different engines and some minor trim differences.
If you look at the driver's side door jam, you should see the chassis number. It would be on the same ID plate as your VIN number, date of manufacture, weight etc.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
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