Morning Winmag - that is looking GOOOD. Commences pondering 870 mods.
That Cavalry Arms adapter is the only one that brings the sliding stock up to the axis of the bore, just like a M16. That has both positives and negatives.
One negative I found out after the post is that the comfy suede cheekpiece raised the sight line too much to work with the red dot sight I have in mind. I borrowed the Leupold off my AKMS, and it was no go. Removing the Eagle pouch/cheekpiece brought everything back together. I may have to investigate a sidesaddle shotshell carrier for the left side of the receiver.