For those who are not familiar with them, the best articles I am aware of regarding 7up bottles are the one's by Bill Lockhart and Cecil Munsey. Check'em out ... but you'll have to do a search on the Cecil Munsey site.
I just realized the pic i posted looks like the 0 could be mistaken as 9. it has a small blob in the center, here is a better view that shows it is indeed a 0