Would anybody be interested in a Anodized replica Aluminium bonnet cover CNC milled to match original costs would be high for first prototypes Pebble finish is going to be hard to replicate but everything else would be fine anodized dark charcoal grey or black
Front and back would match original but not in brittle plastic ( Thinking of light water blasting to give grain finish as they are not smooth)
Otherwise called the "tea tray."
Nice idea, but I'd suggest otherwise. There is a reason that it's made from plastic and there's not sheetmetal there. An alloy one sounds good in theory but in practice it's not great. The part is meant to be sacrificial if the plenum pops off during starting or otherwise (apparently a real enough problem for Alfa to come up with the plastic tray solution to avoid warranty claims on entire hoods).
Also, anodizing is not very UV resistant generally. It will fade to light gray in very short order. And, galvanic action will be a very real problem unless you produce a proper, thick gasket to fit between the hood and the tray. A previous alloy attempt by me (crude!) highlighted the vibration and abuse the panels take. The alloy ate through all the paint at the mount base edge and started to corrode quickly.
The trays are also not flat, they have a slight curve. They'd either have to be machined or bent precisely unless they are made VERY thin.
The fasteners also would need proper plating if touching the alloy. There are a few zinc based platings that play well with Al but again, expect to see some corrosion in short order (I do wash my car with water!).
I'd be interested if someone made a proper plastic replacement that can be painted that will look good for years.
I've reproduced these hood trays in several ways, the most successful was aircraft lexan (clear). They were inexpensive and easy to maintain, are flexible, and show off the pretty intake plenum on the Busso V6.
Hope this doesn't' discourage you if you're set on doing this; I simply wanted to share some wisdom.