'73 Dart Swinger Bumper help needed!!

This is my 73 bumper if it helps you any, and since I recently had the brackets off to slot the frame bolt holes to move the bumper closer in I can tell you that mine had exactly what you have in your picture and no other parts.
In the pic it looks like maybe your outer bolt holes for the bracket are one right above the other? (hard to tell at the angle of the pic)
The holes on my 73 are offset top and bottom for the outer bolts and one right above the other for the inner bolts where the bumper guards used to be.
BUT, the bumper and brackets holes still line up without the guards on.

bumper.JPG