You can't get them any longer, so you must buy full pieces or recipe from the free market, it's not cheap either; I sold a reverse piece recipe for 350m.

Edit: You can't get them the way I remembered getting them(from ToT/PB), refer to the post below.

+1 You can obtain the equips directly from Gachapon. The npc that randomly appears at the end of Root Abyss boss fights can also sell the recipes at random (npc's name is Fredrick, I've gotten both a Tail and Wing recipe from him).

@nitsua2789: I've actually never heard of Gachapon ever giving them, is it like a specific kind, like just reverse/abyss or both?

+1 @keyan22: Both I believe