I don't know what the rules are in here, , so I am unclear how we exchange private info, or even if that is allowed.
If it is allowed, by all means put your telephone and/or e mail address in here and/or send me some kind of message. and I will contact you directly immediately.
Yes, I have a serviceable spare ( as a side-note, 1935-1939 Packard Twelve timing case covers are identical in all respects). I will absolutely guarantee mine as serviceable. I sure feel sorry for the guy - this is not a funny situation !
Should you decide to go into production, I believe you would find a ready market. The difficulty you describe is pretty scary - there are a lot of Packard Twelve owners out there who understand how serious the corrosion problem is - and that it is only a matter of time before they are in the same position - given what that pre-war aluminum is like, and how it behaves even with appropriate care/anti-freeze etc.
I would strongly recommend you try and get the tooling from the now-retired ( decased ? ) fellow who was reproducing them. His were perfect in all respects. Or you can use mine as a sample, in which case of course I will refund your money. Most cheerfully ( if you sell me a repro. of the same quality as that guy from Wash. !)
I am going out to my storage bin - will TRY and photograph my "extra" and post it in here so you get a clear idea of what I have.