Well.... Here's the scoop. My eyes, with glasses, see the number 3963339P. I then went to the good ol' AIM on page 328 it says "extension" should be, guess what, 3963339 and was changed sometime in 1969. I can't see the month or day of the change, but that makes no difference. I do have to correct hood latch assembly.
Thanks for all the help folks! You really did help me locate this item that has been bothering me. Now....I don't have to purchase "another" part and have my original.
3975446 was the replacement for 3963339.