There is a narrative. ..cliff...in JRRT'S later writing. We get this incredibly detailed telling of the tale of Turin, almost to LotR levels. And this lasts through the end of Hurin's story. And then...nothing. Brief sketches and notes and Annal entries for the rest of the First Age material. It's very abrupt, and super disappointing that we don't get the stories of the fall of Gondolin, or Thingol 's death, or the tale of Earendil. For this project, we will be telling all of those stories in detail, and making choices about how to present them. It's the part of the project I am most excited about, because I think it's the area of the story that will benefit most from a thoughtful fanfiction treatment
Yeah, when it comes to how the Dwarves quarrel with Thingol, kill him, and sack Doriath, we'll basically be making up whatever we want. There are a few details from post-LotR writing that are actually useable which I'd prefer to incorporate, but most of what JRRT wrote is Lost Tales material and completely unsuitable to Thingol, Doriath, and the Dwarves as later depicted. Likewise with Earendil's voyages, which were
never written at all... ever. We'll be in total fanfic territory.
I don't think there is any reason to automatically discard CJRT's treatment of the story, and so we'll have to hash out the Nauglamir part of the story when we get there.
But, I don't think there's any reason we automatically have to make the same exact changes CRT did. Giving the Nauglamir to Finrod before Thingol does seem to change the meaning of the story somewhat.
As promised, here's a suggestion how to not change the Nauglamir story (not give it to Finrod) and still give us freedom to tell or discard the Wanderings of Hurin story when we come to it: if Hurin has outlaw companions from Hithlum, they can carry a fairly large amount of gold from Nargothrond and we can potentially incorporate additional stuff from the Lost Tales about all the extra stuff the Dwarves made out of the gold, besides the Nauglamir. If there's major opposition to the existence of the outlaws, Hurin alone can't carry a huge pile of treasure. But he
can carry away from Nargothrond the silver crown of Finrod and Orodreth, and pieces of jewelry and gemstones. Other than spices, gemstones and jewelry were historically one of the most portable, compact forms of wealth, before paper money and bank credit. Even though Hurin wasn't strong enough to dig a grave and bury Morwen alone, I think it's plausible to show him carrying a small sack of jewelry, and a crown as long as it isn't a huge helmet-style crown like Gondor's.
The important part for now is that we want Thingol to be in conflict with an old venerable dwarf *that the audience knows*. So, if that is going to be Gamil Zirak, then we need some important deed for the young Zirak to do, preferably jewelry craft related. For now, we're calling that the original fashioning of the Nauglamir. That can be replaced by something else, but not deleted.
The one argument I see in favor of the Nauglamir instead of Finrod's silver crown is that the silver crown probably should be made about the time Nargothrond is finished, which gives Gamil Zirak an excessively long lifespan. But the Nauglamir could be made later in the Siege, to give the maker a more normal lifespan (not greater than 350-400). However, it doesn't have to be the Nauglamir.
Another option is to make Gamil Zirak the Nogrod ambassador, perhaps the Firebeard equivalent* of Bodruith from Belegost. If Gamil Zirak is a jewelsmith
and the ambassador to the elf-kingdoms, he'll appear in interspecies trades and political contexts -- in Doriath and potentially in Nargothrond and other Noldorin kingdoms. That would potentially let us use him in more episodes than one single work of craft -- though we'd have to come up with political events that call for an ambassador. He might plausibly start his ambassadorial career mid-Siege, but appear before then as a young jewelsmith who visits Nargothrond and/or Caranthir. As Ambassador he could help coordinate Nogrod's cooperation with the Noldor during the Union of Maedhros, and perhaps even during the Siege itself. He could participate in that lucrative trade with Caranthir (though it would expand his lifespan excessively if he's involved in starting it). He could be on screen during Eol's machinations to try to stir up unfriendliness to the Noldor among the Dwarves -- Zirak could be either for or against Eol's message.
An ambassadorial position also gives us opportunities to really flesh out his personality, in preparation for how he will quarrel with Thingol. Do we want Zirak to be overly proud and easily offended? Or somebody who doesn't take offense easily, even from Caranthir? Somebody who soothes tensions, or tends to enflame them? Smooth-talking, calm-talking, purposely a jerk, or foot-in-mouth? We can think about how we want to set him up for his role in the Nauglamir quarrel, and then display his personality through his diplomatic interactions with "Naugladur," Thingol, Azaghal, Bodruith/Bodaruith, Finrod, Eol, Caranthir, Maedhros, etc.
EDIT: I don't mean that the details of the quarrel with Thingol should be worked out in advance, but that we can decide a rough estimate of how much of a jerk Zirak is, and how much of the conflict is Thingol's fault. I think we have huge latitude here -- as long as Zirak is at least somewhat sympathetic. Even a hothead like Turin has readers who like him.
* not the word I wanted. what is the word??? com-something? contemporary? complement? compatriot? coeval? coequal? corrollary? not colleague