It is a gw model therefore accurate of a daemon and more than 50% gamesworkshop pieces (100% > 50%)
It's also a Lord of the Rings model.
I don't believe GW ever made the distinction.
Hm. It appears the restriction is for Golden Demon and maybe White Dwarf photographs. Carry on.
New Line Cinema had a thing about LotR figures not being used as part of GW's other products. GW was forced to sign lawyer like papers saying this is a big no no. You won't find anything in any GW rule book, article or internet spiel that in any way encourages folding LotR models into any other GW product.
That being said, they are solid models, fit with the games, are to scale, and I doubt very much that if we allow them any New Line Cinema lawyers are apt to find out about it. I also don't know if any legal obligations get passed down to Derek as a seller of GW products.