I spoke to Doug and he says a 69 Sheet wouldn't indicate that like a 70 and up sheet. Also he knows of no documentation to support what I said.

When I get a chance I'll look at the #'s on the spare that's sitting in my basement and compare them to what I have on file of my old Coronet.

So I stand corrected. I was certain I learned it over the years buy going by what I've seen in trunks and what I was told by others has been disproved.
Sorry for the confusion.
Ron