If you right-click on things in the Append… structure, say Objects, they’ll go light purple… tag a mesh and it’s associated empties and armatures and it all stays connected like it should. (highlighting the importance of descriptive names) Lacking that, just tag every object and force it to a specific empty layer, then delete what you don’t want and put it on your in-use layers…
Thankyou thankyou!
I don’t know why I didn’t guess you could right-click names to select more than one, or that the A key would do it’s normal All function.