I noticed my front takedown pin hole is ever slightly oval, presumably from usage and wear. The pin inserted without an upper has a very small play to it. Everything else about the lower looks to be in great shape. I cannot see any other wear points the be concerned about. Rear receiver plate looks to be perfect. There’s this reinforced receiver tab welded inside the lower where the front takedown pin goes, is this factory or did the previous owner add that to slow down the ovaling?