You may have an easier time making one than finding one. The plate is fairly simple, and they are extremely hard to come by as someone would have to pull it off a parts car. Even the CSi airbox is difficult to source. Took me 6 months to find one, though luckily I already had the bracket, though I do recall one coming up for sale here just a month or so ago.
Gerhard sells those... last I heard he had one left. In Waldbronn.
Postal code 76337 in Germany
Hi James,Thanks for the tip! Never heard of Gerhard before but Waldbronn is just 45mins from me so I’ll look him up!