I've noticed a few Topics asking about missing polygons and crashes in Red Dead Revolver. Unfortunately this is one of many Xbox1 games that just barely met the standards of backwards compatibility, and because of that there will always be some amount of polygons disappearing. Also, as I understand it these problems are some of many odd graphical effects that can show up when playing Xbox1 games on the 360.
Another problem problem mentioned (that I personally ran into) is that in Chapter 8, and a few points later in the game, the game can lock up. There are ways to play around it in Chapter 8, but the later points are unavoidable.
Here's the only solution I've found: set the 360's screen resolution to the lowest possible value, which is 480 for most connection cable types. I don't remember if there's any difference between 480i and 480p, but I'd say play it safe and use 480i if you're given the option (the only reason I mention these differences is because each type of connection cable has different resolutions listed). Anyway, it's been months since I played the game but I believe this fixed all of the hard locks (since I finished the game), though it didn't get rid of all of the disappearing polygons.