theres 3 layers to car parts.
OE (original equipment), OEM (original equipment manufacturer) and aftermarket. car manufacters assemble other companies parts, either to specfication or off the shelf, so what you are describing is normal.
OE is what came on the car from the factory, usually produced by an OEM with the car makers logos/part numbers applied.
OEM is made by the same companies which made the OE part, or by other companies who make OE parts for other makes/models but not necessarily the part on your car. Generally the quality will be just as good as the OE.
Aftermarket is parts made by companies who do not supply to car producers, and parts can vary in quality from substandard to better than OE spec eg. chinese noname brake pads=substandard, powerflex bushes=superior to OE.
Usually what youll find is that the OE part, as you found with the cv joint, will be also retailed by the OEM of that part for a lot less than you can get it for at the dealer. ive read on other forums of some parts by lemforder made for mercs, that when sold under the lemforder brand retail, simply have the mercedes logo ground off.
Hella are an OEM, so the quality should be good
why are you after a pedal out of interest?
