Make it... done it for my MKiii and mesa Metal grille front stack.
The wicker material is available easily online on rolls, used for chair seats, etc.
Remove the current grille. I then made a copy of the wood frame in ply, soaked the wicker for a while and then stretched and stapled it to my frame. As it dries it tightens up. Then just screwed it back in. The screw on logo was easy to swap too. Basic tools.. jigsaw, staple gun.
Not tried with a Mark IV but I sure it will be similar process to work out.