Front rear and side vent grill replacement mesh.

That’s where my man in Warrington comes in.
M

The 'crinkle' stuff is what I used. When I was looking around for material, I'm pretty sure that I spoke to The Mesh Company and they were very helpful but I was drawn in by the absolute bargain from China (It cost me about £15 to do the whole car and I've still got some left.). I was looking for Jaguar mesh (I was thinking of the S Type grille).

If you are feeling flush and don't want to get your knuckles damaged cutting wire mesh, particularly stainless, which is as hard as hobs from hell, MGOC sell kits.
The front lower mesh comes with the brackets in place to fit, part number DQY000100PMD for the front lower only at £39.25, also screws to fit, you could fit others, they are at £2.05 each which seems steep.
Also spring nuts which are a plate affair, but you may already have those.