Don,
I've seen a number of variations in the weight of the fonts along the bottom. Verne Frantz's original label and Sam Griffith's original show the differences quite obvious. I even checked out a couple more at the Gibb Show this weekend.
Again I say, these things were furnished to GM over a number of years and likely came from a number of different vendors (or maybe printed in the individual assembly plants ???) so who's gonna be the "expert" to stand up and say "They should ALL be EXACTLY alike!!!"
I'd give your version a 99% approval rating!
GO FOR IT! 