Those are chassis numbers - MB uses numbers to designate designs. W124 was produced from 1985 to 1993, I think, etc. Part numbers for parts specific to that chassis will start with the chassis # (124 xx xx xx). Confusion comes from when that part is used on other designs, too -- the new links for the rear suspension for the W124 are actually W210 parts, the steering coupler for my W108 is actually originally a W111 part number, superceded by a W115 part number, etc.
The chassis number will be the first part of the VIN number on older cars (e.g 108.068 12 xxxxx) designating design and variation (in this case a 280 SEL 4.5 with left hand drive and auto tranny). Use that number if there is any question about what part to order.
Later models have a "US style" VIN, but it still includes the chassis number along with some letters and always starts WDB
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!