Sorry.....I'm stuck in '67 land
I know very little on 68 & 69 especially when it comes to Z's and X codes.
But, in the case of this thread, I think what was stated about the wrong sticker applied initially makes sense. I wonder what can cause a 'wrong' sticker to be applied in the first place. It's my understanding that the sticker is affixed during car assembly.
Here is a link to some of Don's work. Notice the differences in fonts.
http://www.angelfire.com/rock/69ss/frame.htmlSelect specialized decals and you'll see a selection for Camaro tire pressure decals.
Mike
PS. I did approach Don about making the 'R' sticker, being he was looking for a good original before, and he said he was no longer making stickers.