[Aiwendil]

NA-EX-45.2: I’m not sure I understand what you mean here by:

Since the band that captured Gwwindor had no captives, I inserted the discription of them here.

It looks like the description of them has been deleted (as it must be):

But scarcely had he determind on this {than they heard the noise of a great host approaching through the forest from the south;}> NA-EX-45.2 <editorial bridge ; when
><Lay
{ __ Their spoils were piled,
...
he defies fearless, __ on a fangéd peak
of thunder-riven __ Thangorodrim.'

In}in eager anger __ then up sprang Beleg,

But I think there’s further difficulty here. In the Lay, Beleg’s sudden anger (and hence the whole dialogue that follows) is caused by his hearing from Gwindor of the mistreatment of Turin by the Orc-band. In the CoH story Gwindor did not see Turin. However, we might be able to recast it (and now that I think of it, perhaps this is what you intended) so that Beleg’s ‘eager anger’ is caused by his realization that he followed the wrong Orc-band. I would suggest this:

If this were so, his sole hope lay in returning to the Ford of Brithiach, and then going north to Tol Sirion. {But scarcely had he determind on this {than they heard the noise of a great host approaching through the forest from the south;}> NA-EX-45.2 <Lay
{ __ Their spoils were piled,
...
he defies fearless, __ on a fangéd peak
of thunder-riven __ Thangorodrim.'}

In eager anger __ then up sprang Beleg,

NA-EX-47.6: Ideally we would provide both the Elvish and English names. However, the Elvish name doesn’t work here since it alliterates on the second stress of the half-line (the alliteration in the second half-line must always be on the first stress). Conceivably, we could try:

That song he sang __ is since remembered,
by NA-RG-54 {Gnomes}[Noldor] renewed __ in Nargothrond 505
it widely has wakened __ warfain armies -
{to battle with Bauglir - __} NA-EX-47.6 <CoH ‘Laer Cú Beleg'> __ 'The Bowman's Friendship’.{1665}

However, that has two drawbacks – first, the _ A A _ alliteration scheme, while technically valid, is not so good and hardly ever used by Tolkien; second, we rather lose the point of ‘widely [wakening] warfain armies’ without ‘to battle with Bauglir’. So I think I prefer to leave it as in the Lay.

It seems strange that an Elve from Dorthonion should say that he wandered since the Nirnaeth

It does seem strange, and I wondered about that when I read it. But after all Tolkien wrote it (presumably J.R.R.; I doubt very much that CT would have introduced such a statement in CoH), so I think we must let it stand. It may have been a slip of the pen, but one could imagine that perhaps they joined with Fingon’s folk after the Bragollach and later fought in the Nirnaeth.

NA-EX-57.1: I’m hesitant to introduce such a small detail. If LT provided substantial information that would be one thing, but to break a sentence Tolkien wrote just to add (essentially) that the host contained wolves seems to me unnecessary.

Also a general comment about moving back and forth between the Lay and the prose sources: I think we may be overdoing it with the editorial bridges. In many or even most cases I think we should probably eliminate these and simply move into verse without comment.