Neither Chrysler or Mercedes makes the switch assembly. Parts like this are subcontracted to approved suppliers who may in some cases subcontract it out to some other company.
The Mercedes part number is on it so that it could possibly be used by them on another model car in the future, it would save them from designing something similar in the future.
The Chrysler number generally appears only in the Chrysler computer system with a cross reference to the Mercedes part number. If the part is still available they will buy it from Mercedes and mark up the price generously for you.
No company made the micro switch specifically for this assembly, it is a standard shelf item from some maker of micro switches and would be in a catalogue. These switches generally are made to a specific sizes and are often interchangeable with other makers switches if they are commonly used.
A little investigation should turn up some alternatives. Maybe the switch makers name and part number are on the switch, removing the numbers would make the part more expensive to make due to the plastic mold having to be modified.
Keeping costs down is the name of the game.