Its a Land Rover Genuine part
Contact any decent main dealer or parts retailer, should be a stock item
Not cheap though
I know that Duckworth LR (advertise in the LR mags) sell them
Bolts to chassis via holes you cut in the bumper (like a bull bar/a bar) and just sits out front
But, why not just get a proper winch bumper that wont ruin your approach angle?
:D