@ZoeyZhou
1) Polish the lock and keys, and they will look like new again. It only takes a few minutes! (You can also buy a new set at the store - but that's a waste of money in my opinion since polishing it will work just fine).
2) You need to bring your items to Louis Vuitton to receive a personalized repair estimate. If they accept your repair request, they can definitely change the handles on your Speedy DE and Speedy DA, and redo the pipping on the Speedy DA.
For more details on repairs, visit the LV FAQ subforum.