Good news folks! I contacted Greg Clauss at Clauss Studios, who as you probably know makes a lot of repro rubber parts. He is willing to make a reproduction of the triangular airbox cover that is simply unobtainable.
Now the only problem is to find someone who will loan him the part as I don't have one. Can someone who has that part loan it to Greg for a week or two so he can copy it? It won't be damaged in any way and for your efforts he will give you a free copy.
Someone please step up to help the rest of us out and PM me. Thanks!!