Yes, the bottom is a sling mount. It clamps around the magazine tube and is secured with an Allen head cap screw. The ring for the flashlight is clamped the same way, both are recessed a bit so it looks clean.
12 gauge, synthetic stock that’s been replaced with a Hogue, 12″ Overmold stock. It’s a great gun. Mine looks similar to your but with a different flashlight mount.
