Thanks for the replies. The stock is a Nordic Components CRS (no longer made). It's shorter than the other "PDW" stocks out there because there's no buffer tube. It was simple to mount to an XCR fixed M4 stock adapter. I'm not sure that it will stay on the XCR, I still have my ACR stock w Ezed adapter. I'm getting a shorter barrel and mini upper from NavalBeaver, that might help it balance a little better.
You can't get a cheekweld with this stock. However, I shoot "nose to charging handle" and rest my cheek on the adaptor.
CRS Stock:
Nordic Components Compact Retractable Stock AR-15 Dedicated 22 Long