Quote - Easiest probably is to save it as a scene. (PZ3 file.)  You can then merge
the whole thing with other scenes, using the File: Import menu choice.

Is it possible to load a .pz3 file and literally mege it with another?

When I load a .pz3 file it is loaded in as a whole new scene - I dont get an option to merge the current scene.

Am I missing something?