Well, here are my arguments:
First of all, welds on the frame should be avoided. Not only because the frame does flex. I would never rely on anything only
welded there, even if it was the best welder who did it!
2nd, if all you want to pull with it is a 3/4-ton trailer, your setup should hold fine. But don't even think of tow-baring another Deuce and having the safety chains attached to those shackles, way down there!
3rd: Knowingly, what can happen, will happen.... There will come a day when you got stuck in a ditch or in soft ground, heavily loaded - and someone with a big truck or heavy tractor will try to pull you out, same way you went in. Guess where the recovery strap (or worse, a chain) will be hooked up to.....?
For safety, I'd move the pintle hitch and D-rings back up to their stock height and position. Then run a pair of L-struts, from the frame down to the receiver hitch. Bolted to the frame, of course!
Here are some ideas: