What do you think about sizing the ring to use the silver or black aluminum HMMWV M1025 turret bearings? I see a couple different LSV variant M1161s, different superstructure over the back deck. Use the bottom side rails welded to the diamond plate as the roadmap for the top side rails, as far as the diameter of the round lugs on the ends that the bolts pass through?
This top/rear view of the gun ring shows some good detail, inverted U shaped, the bearing radius protruding past the rear edge, lots of lightening holes, depending on the superstructure width, the HMMWV early turret bearings could work. bolted to the underside of the gun deck, and the weapons mount, back pads and traverse lock attached to the bearing inner ring.