Are you referring to that rectangular cross-section tubing painted red in this photo:I haven’t located the bars that attach to the radiator mount shown in your photo.
Here's my picture, though since my car is assembled I think RPHIL40342's shots are better. This is the side I re-made using angle iron. Wish I could show how it is attached to the body, but the camera just couldn't capture it from that angle. Basically two machine screws installed vertically. Notice that my improvised angle iron (and I think the factory tubes) are bent slightly upward just ahead of where they fasten to the body.Thanks for sending the photo - hard to see much.
Might you be able to take a couple more brightly lite photos at all the points of connection?
It serves more than an ornamental piece. It's to make noise when you hit something..... And, as someone pointed out, the Duetto / Spider bumper is more of an ornament then an actual safety feature.
The bumpers are adjustable using the brackets in the very fist picture. The grille is fairly fixed.Given that, it seems the bumper and grill attachments need to allow for adjustment to get the "look" and alignment just right.