Check your triple tree and sight insert. Look for possible strike, drop damage that might have bent the triple tree out of alignment. Also inspect the sight insert to see that it is seated correctly and not damaged.
Give a good look at your mint FMP rifle to be sure it is not actually a refinish. It would seriously surprise me if it left the factory that way.
My next thought is please post up how it is marked, reciever and barrel marking (The issue FMP barrel I have is marked just in front of trunnion with FMP, the date, and some other info) Hopefully Tony will be by to verify if it matches up correctly. FMP recievers were also imported and used to build demilled G3 kits so it would be best to rule that out.
One last quick thought, pyll the rear sight and stock and take a carpenters square (90 degree type not the triangle), check the rear sight base is square to the reciever rails. You should be able to lay the square across the flat on the top of the sight base and then across the rails on the sides of the reciever, check both sides and you can verify if rear aight base is square to reciever.
Have you put a laser boresight in the chamber and a paper with a line on the far wall? Line should be leveled straight up and down and about 8 inches long. If you have a rifle vise it can let you more easily document your sight alignment. This is a builders trick when setting your triple tree.