As with a lot of things Ford, Ford used multiple suppliers..
So we have to take heed before making any final judgements....A general consensus is always best I have found before jumping to any conclusions. All I know is that All my original keys for both of my cars...and they are the originals from new, All have the H instead of the I. I just assumed that Ilco with the "I" was the Repro.. I in no way ever thought that it was a NOS key though it looks like one. Interesting to know that story Rick... Interesting.
Oh, and about the USA being there. I have actually found some original "H" Blanks with them, and some "H" Blanks without the USA marking. so I would say that they came both ways...With and without the USA, but with the USA marking was definitely more prevalent.
Tony K.