* The "Missing Parts" Quest: This involves finding three parts: the Gear, the Screw, and the Spring. These are found in various locations around Johto and are needed to repair the "Time Machine" in Ecruteak City.
* The "Old Charm" Quest: This involves finding the Old Charm hidden in a specific location and giving it to a specific NPC to unlock a hidden area with unique Pokemon.
It's important to note that these are not exactly machine parts, but they are items that are required to advance the story or unlock hidden content.
Perhaps you're thinking of something else? Could you provide more context about what you're looking for? For example, you could clarify:
* What specifically is the "machine part" supposed to be used for?
* Where did you hear about this quest?
Providing more information will help me give you a more accurate and helpful answer!