Ok for clarity, the frame extension is forward of the photo area and not any part of this problem so please drop that.
Second the owner or previous owner (Brother knows the guy as a neighbor) have not in anyway overloaded the the tow hitch so please stop with the arm chair quarterbacking saying it is possible owner overload. It just did not happen. Both present and previous owners towed within the weight limits and tongue limits. they only towed a small trailer with a golf cart on it and regular within limit toad.
There does look to be a welding blow thru at the l bracket but the other side cracked also and there is no bracket or weld there.
And no I am not mad or ill tempered about any of the posts, I do have a direct manner of communicating and can be sarcastic.
Lastly, on another Forum, it seems someone else has identified this problem on their rig. Which to me is a small success because that is one less tragedy on the road and means tat getting this out has a positive effect.
Thanks all for your inputs and keep them coming