I'm missing my tray too (72 LT-1). The local 'vette shop doesn't have any but can get me a tray for $100. However , the price doubles when the mounting pieces are added!!!!
I have an alternative though... I have a friend that has recently opened up an auto machine shop -- they do custom pieces for, well right now it is for Porsches and old (20's, 30's) Fords I think. But he says that if I can get him a tray to copy and if there is some demand for them, he can whip off some trays.
Not sure how much yet; I'll see if I can get a ballpark figure from him.
Now, my question to you people is, is there a demand for a reasonably priced, newly machined tray and mounting pieces? Let me know how many people might be interested and I'll pass the info on. Then I'll come back with more details.