[MrForbes]

No, it's not legal. The bolt heads that hold the bracket to the frame, behind the bumper, are legal, but the bolt head that holds the wheel to the bracket, is not legal. And the way the bracket is attached to the frame, it's not quite legal, because the FRAME PERIMETER is defined by the largest part of the frame, which is the bracket, and the frame rail needs to be out a bit further (the thickness of the bracket) to be legal.

you could add a shim to the frame between the brackets, this would make the frame itself be as large as the FRAME PERIMETER.

And you might be able to use flat head bolts for axles, to keep the bottom of it legal.

The bolt heads that stick out of the FRAME PERIMETER within the BUMPER ZONE are legal, and you can just pocket the bumpers to fit over them. I'm assuming that these bolts that hold the brackets to the frame rail are more than 10 inches, and less than 16" above the floor.