Another player on Order brought it to attention that any ancient or adult Lunus can accept and do the quest Lunus Path 3.1: Create a Hardened Silver Claw. However, only Lunus dragons who did the RoP after the change around to the questline is offered it. My ancient who did the quests back in 2010 isn't offered it, but the one who did it in 2013 is.
I don't really have the time or patience to scrounge up the fragments myself and follow the questline through to see if it allows you to do the RoP again from that point, though.