[I] Old - NPC's appearance cannot be changed.

[Triple J]

Nothing happens when attempting to change any of its parts. If they'll never work, those options might as well be removed from this NPC.

[Cordelia]

I too have been having this issue. I am not sure what the cause is, and I'm also not sure if the Old NPC is even able to be edited yet. I hope this will be fixed eventually.

[AwesomeJRFD]

In the game files there are no sprites for old NPCs other than the default, and code editing does nothing. I assume Runouw just copied the code from the normal NPCs.