Top part of the "How to make the ELABO's pennib" panel

On the issue of the potentially confusing terminology, going by Pilot's nib types overview page (in Japanese), the FA nib is indeed the “Falcon nib”, whereas this suggests the nib on the Pilot Falcon, aka Elabo, would be "the Falcon's nib" in contrast.

Source page:

https://www.pilot.co.jp/promotion/library/014/