Add rig to mesh attached through socket

I have a pair of handcuffs that I put on a dead NPC character. By design the handcuff only goes on one hand since the other side is attached to a key that dangles from their dead hand.

I created the handcuffs and the key as a separate static mesh and attached them to the NPC mesh using their BP and a socket that I created on the NPC skeleton. However the handcuffs are obviously rigid and don’t have the same skeletal ragdoll as the rest of the body. So I want to add a rig/skeleton to the handcuffs+key. Should I just create that in Blender and update the static mesh component to the new rigged one and expect it to work as it is?

I understand it is a quite specific situation, but I think there is a useful generalisation of concepts behind this specific case