Mystery AR-15 Bolt and Carrier

About week ago when I brought lowers from a FFL that I love for buying lowers and transfers. I asked if he had any BCG with shot-peened 158CM HPT/MPI bolt, he said "I dont but I have BCG that you can have". He sure did made my day! Sure I internally recoiled when I saw the condition of the carrier, it looked like it might have saw a flooding. He came out of the back with just the bolt and carrier then he completed it(bolt itself is already complete) using his parts drawer thereby the cam pin, firing pin, and firing pin retainer are not in consideration for identifying the BCG. The guy's more of a seller for lower end kinds of stuff like Anderson and PSA which might help in identifying this BCG as it is fairly unlikely for it to be anything higher end. But there are distinct features on the bolt that I believe would result in this bolt successfully identified by you guys. Like the faint groove which I point out in the picture also the scallop behind the bolt lugs which is behind every single lug without a miss. Also, the machining on the bolt is beautifully fine and well done. The ejector is very beveled which is another distinction that might help to solve the mystery. The extractor has o-ring and insert. The carrier underside is finely machined also the gas key is aggressively staked also note on the rear screw you can see how knurling on it is very deep, unlike some shoddy faint knurling I have seen on many cheap allen screws. However, I'm irked by the visible grain of steel on both sides of the carrier which is also distinct itself, also, of course, the lack of marking on the bolt.

Link to the album with photos of the bolt and carrier below

https://flic.kr/s/aHsmND74Ds

(I wanted to have the photos large displayed in this post, how do I do that? I have tried attaching but it does not look like other post I have seen here.)

That's a F on the Carrier which means it's a FN carrier. As for the bolt, I have no idea.

That should clean up fine and be a good part.

@sig1473
I did not see any "F" marking on the carrier but upon reviewing the picture I can see what looks like an "F" marking on the left side of the carrier but it is not marking of F just deep gouging or pitting.

Wait. Well... That's interesting, the more I tried to take pictures which show how I see it, how it does not look like "F" to me, the more picture shows convincing "F"... I decided to google FN bolt carrier to see if the marking is even in the same location and sure enough! That damned "F" it is in the exact location and often faint... You nailed it! Thank you sig1473 this mystery is halfway solved!

Link to the album with two close-up pictures showing the faint "F" marking posted below.

https://flic.kr/s/aHsmNFaZfY

@Esq.
Agreed I'm confident that it will operate just fine from my close inspection showing the parts to be of quality. But there's part of me, my imagination running wild about it failing, an irrational fear that the bolt is made in China out of garbage steel that somehow successfully fooled me of it's quality status. As I fire it, all lugs shearing simultaneously at first shot, before the chamber pressure even peak, releasing 60,000 psi, permanently disfiguring my face, forever marks a stupidity of man who would shoot a ???? bolt like a drooling retard.

It's better to be cautious than sorry, right?

Actually... I've decided. I won't shoot that bolt until it's identified.