Question Can I attach a prefab to an existing object in the editor?

I have an unpacked object in my scene that I want to attach to an existing prefab. It has the same structure as the prefab, just some of the components are configured and linked to the scene. Ideally, any attributes that are different between the object and the prefab would retain the objects settings as override values.

Currently, the only way I'm doing this is to pull a new prefab instance into the scene and replace the existing object... but that means I have to manually link the new instance where it is referenced in the scene, reconfigure buttons that call scene object functions and manually position the instance. Would be much easier and less chance for error if I could just link the object to the prefab.

Is that possible?

 

Don't really want to revive dead thread, but if you found any solutions could you please share it ?