What is this strap/bar on Aussie K-member?

1WildRT said
If anyone is gonna know Jeff AKA Oz Hemi would be the guy, might give him a call... Or shoot him a text with a picture of the bracket...

Well, I just "Stumped the Band", in Johnny Carson-speak, as Jeff doesn't know what it is, either! (Dammit!)

But he's going to send the pictures to his Aussie friends/connections for me, so we'll see.