John;
Thanks for your reply.
Yes I have seen that link and there are some holes in that database.
I also have this enquiry. In this case I do have what is supposed to be the CN. It also was owned by Aero Service Corp in Philadelphia.
N9375R 891-100 Aero Commander
Since Aero had an Operation in Canada, it is possible that one or both were exported there, though because of Canadian law they would have been to Canadian holding companies.
Canada's online database does not go back very far.
Bob