DarrylG said..
Just turn the tail piece upside down and drill new holes ?????
Genius!
Laminate a tight fitting (carbon) tube in the tube of the vario boom end.
Then fill the slot with layers of carbon/glass fabric and epoxy resin.
Instead of carbon, you can also screw in a piece of aluminum or something else that you like.
Cover it with a layer of carbon, sand to the correct diameter.
Drill holes, a little spit on it and you're good to go : )
oh, and look for what caused it...