Gorgeous build! Worth bookmarking for inspiration when I start a "made-in-USA" version so the girlfriend can have her own iron for Service Rifle matches when visiting rather than having to pass my M16A4-clone back and forth.
Right now, since slingplates can't be exported to the US even when they CAN be had up there, I'm looking at a functionally similar but not identical plate from Odin Works, unless either somebody down here clones C7 or L119 endplates, or True North Arms clones 'em like the "Hook" CH latch and finds a way to legally export 'em.