I picked this up from Henderson Precision (the case trimmer guy) a couple of years back but never got around to building anything with it. Not entirely sure of the exact stock model, but it looks and feels a lot like a U-1, which would make sense. It’s customized with an M-Lock Arca rail, M5 cut and pillared, designed for a Rem 700 clone with a side bolt release. Asking $720 shipped. I have both the weighted spacers and reg spacers I'll ship with it.