I put the latest photos in the original post, and changed it to the current specs.
I do like the Magpul XTM rail covers better than the Tango Down panels I'd been using. The TD covers slide off the front of the rail, so if something was mounted in front of them, it needed to be removed first. Their shorter length makes them more flexible.
I've attached the Surefire M951 weapon light. I installed a Malkoff Devices M61 LED module into it. It now puts out 260 lumens in a nice wide pattern with lots of spill. It's activated by a tape switch located at the support hand thumb position.