There is a scene from very early in Mandingo's career that has him in a white gazebo just slamming it into a rather ugly girl in doggy position. I have never even seen a hint of that one online. Good luck finding that one.
Other than your characterization of the girl's attactiveness, you're describing to a T his scene with Katie Morgan in
Chasing The Big Ones 12 in the first few weeks of her stellar career, with her pre-surgical body. Indeed, it seems to have disappeared online for now.
Mandingo certainly didn't think Katie was ugly; he dumped a massive load on her ass two minutes of screen time after he first entered her, even though he pulled out a couple of times so that he wouldn't cum earlier. But they're not done: he fucks the overmatched girl on a mattress, gives her "four or five" O's in multiple positions, and she finally brings him off again. Awesome scene(s).