Since DLC41 HOL promethium lockboxes have been removed. But that was the only way to drop the "Avatar Bombardier Variant Head Style" for the feat. I've looked on every vendor, but it looks like they missed it.
In the Archive of Victory. The Aeronaut Variant head style is there but not the Avatar Bombardier Variant head style.
The Avatar Bombardier Styles are available from the Rewards From Time & Space Vending Machines for Quarks, but I can't recall if the Variant Head Style is being received from the Scaling Boxes you can purchase for Quarks.
