I actually like the '71 better myself, the '70 version looks too clean. :D
But yeah, AMD isn't making the '71 rear bumper yet. Have to find one re-chromed or have it done. But, there's a reason why it costs 3x as much as a reproduction. The re-pops aren't made here. It's great that they reproduce them, but the original stuff is better. And you should be able to use '71 to '73, they all used the same tail lights at least.
Here's a '73. Pretty much the same, the rubber bumpers are larger but I think they're mounted in the same spot. Not perfect but in pretty good shape
https://www.ebay.com/itm/142068147380