Since no-one else has posted, I did my VY grille a while ago, used black aluminium mesh, though. You can buy the mesh from auto parts stores. I cut out the vertical cross bars and spent ages bogging up the gaps that were left, then simply fibreglassed some short pieces of wire onto the back of the grille, cut the mesh to the correct shape, laid it in place and bent the wire over to hold it in place, lot of work and lot of effort, but looks great. Have a look in my profile album for photos.
You may be able to buy them, not real sure on that.
'Ah well, I suppose it had to come to this.'