One should exercise caution and refrain from succumbing to the allure of an aftermarket door lock.
Upon examination, it was seen that the Part number was indeed there; nevertheless, it was noted that the electrical connection had dissimilarities.
The determination of whether the connection is a 4 or 6 pin configuration can only be made upon its removal.
Unless one has exceptional skills, it is advisable to entrust the task of replacing it to a Mercedes independent mechanic. In order to remove the rivets, it is necessary to use a specialized torx bit, which is only available at authorized dealerships' workshops. The work is of poor quality.The torx bit was obtained by my technician from an acquaintance employed at the dealership.
To get the appropriate component, it is recommended to visit the authorized dealer with the Vehicle Identification Number (VIN).
In the month of June, I procured a Mercedes component, which amounted to £202 after applying a 10% discount.
Regarding the part numbers mentioned, it is seen that A204 730 12 35 is included in the Electronic Parts Catalog (EPC), however A204 730 40 35 is not found in the aforementioned catalog.