Sorry to ruin this for everyone but you cannot buy the r-line inserts seperately!
If you want one you will have to pay the full price of the bumper, which at the moment is around 527 plus vat.
I have the bumper, and i made a boo boo with mine with the exhaust being near it, luckily it was fixable! But when i rang VW and asked for a new black insert? They said no!
So be careful!
I do have a spare insert though! As i said, i sorted mine luckily! By looking at your photos that is nothing like the r-line shape? You would seriously struggle to make the genuine r-line insert fit into there? Its a completely different shape