Here’s a clip with foley for 3PO, harvested from good ol’ Revenge of the Sith.
https://vimeo.com/246613493
password: servo
Almost impossible to hear any 3PO walking here, it needs to be… more intense! And I would suggest slightly zooming in on sad BB-8 at the 8 second mark to hide 3PO’s leg which should be walking away at that point. Alternatively the leg could be hidden by placing a new R2 image over it, I could try something like that. Even though removing a golden leg would be the opposite of alchemy, really.