How to get a reference to actors placed in world during runtime? (making a save system)

Hey guys! I am wondering how I can get a reference somehow to the actors that are placed in the level and not spawned during runtime. The reason I need this is because my save system will need to also restore values after load to specific actor instances that are not set to be spawned, but are already placed in the level? Is there a way i can get some kind of an instanced name that the editor would use and use that to resolve a pointer to the actor after the level loads? Thanks!