Gunner, yes, that's the Robarm fixed stock adapter - just needs a bit of machining on the adapter part itself and on your buffer tube.
FWIW, those four envelopes went out in the mail today. Hopefully you folks should have them for Christmas.
That's the Bravo song - it's looking like a battle carbine Christmas ;D
FWIW, I'm going to duplicate that stock set-up on the next XCR as well.