Got this assembled, and will test fit internal moving parts tonight. Quality externally and on parts is high. Biggest downside is things are VERY tight fit. the magazine release will need to be upgraded to the extended version otherwise it may prove hard to use with gloves. The trigger guard is really too "wide" around the safety selector area, again making it hard to use.
You'll need various parts (trigger, trigger bar retainer, trigger bar, safety selector, safety selector detents and spring, mag catch, mag catch spring, mag catch plunger, mag catch spring, dust cover trap door assembly) to swap into this stock. I was able to source all parts except the safety selector detents. Currently having them drawn up in cad and hope to 3D print..
The takedown button area is a cause for concern in regards to wear. An easy win would be to reinforce that rear with an metal insert, but we'll see how it does long term..
SI SMC-90: https://alnk.to/bPhb6B0
A3 Tactical 1913 modular VFG: https://a3industries.com/compact-modular-vertical-foregrip-w-hand-stop/