Few explanations about the method to do it, but I have found nothing conventional to apply here on this initial particular (but well working) way of rigging a wing.

This was mainly manual editing (so not sure to remember all the steps) :

 - define a center and set a center bone at this location
 - parent the first wing bone to this center bone
 - rename the bones with .LEFT as suffix, select them all and "symetrize" to obtain the .RIGHT bones
 - duplicate wing parts and feathers and scale X, -1, with the center previously defined as pivot
 - Edit each part of the right wing in order to arrange the normals
 - Parent (with automatic weights) the wings (not the feathers) with the armature
 - For the feathers (on the right), select them by group (object mode) in order to bone parent to the corresponding wing part

And the result as given in the comments above : <img src="http://blend-exchange.giantcowfilms.com/embedImage.png?bid=1507" />

Nothing "magical" !!