I have this Layout, with 5 Bodies.

I have done "Insert Into New Part", and Inserted all arcs into another part:

I need to add Triangle to Arcs (not overwrite, only add as a body to existing Part File). I can't figure out how to do it. Because, when I do Insert into new part, Solidworks overwrites the previous file instead of adding additional bodies.

This is an easy example of course, I am referring to more complicated Weldment assemblies, where drawings had been made. And in times when you need to add one or two more bodies to exported Weldment (Saved Externally with Insert Into Part) , I don't really know the way to add them, without overwriting the previous file and loosing all connections to drawings.

Please help!

P.S. in case anyone wonders, sign is from Harry Potter, Deathly Hallows.