Oh, you would want to group the wing, engine and the laser cannon first anyway.

Then duplicate...

And then move the group up or down to whatever position is fitting.

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If you have grouped a set of objects, this group is selected this way;

1) Klick on one of the objets you know are in the group.
2) Press the up-arrow on the keyboard to select the (first) group setting.

If that group is a part of a bigger group, press up-arrow again to select the bigger group.