Apollo/Kitty Hawk Cover

Found this in the pile of covers my grandfather accumulated from pharmaceutical companies. They would send advertising in first day covers, or in folded sheets containing a medical-related stamp.
I know it's only worth a few dollars, but I was wondering more about the cut of the stamp. If you look closely, it's cut rather crooked. Is this common for this stamp, or would they have come in sheets and been cut by whoever placed the stamp on the envelope?

andere, No this is not normal. It looks like someone got tired of pulling them apart and used scissors and cut them cockeyed.

I will agree with revstampman.

I find that amusing. So it's counted as more of a 'user error' and not a manufacturing error, correct? It adds some character to the cover.