better to look at the K factor on the rear of the instrument. VDO calibrates them to a factor that MB uses, its the "Konstant" or K factor.
I never wrote down the K factors over the years I've messed with VDO speedometers but that is the key thing a speedo shop uses. Not the faceplate p/n.
Are you aware that speedometers also age as the magnets lose some of their pull against the rotating drum inside the speedometer? Swapping in a used one may still leave you with an error as most old speedometers are off
If you like the speedometer and its got clean odometer wheels, I'd just carry it to a speedometer shop that knows what they are doing and let them cal it. Or leave the car off and they will nail it down to within 2% (as close as you can read the pointer)
BUT if you insist on using the faceplate# here's a thread on this subj.
Speedometer part #
I note that 123-542-03-67 isn't listed.
Also I suggest you use the search feature on this matter as there is lots of info already available