thanks for the link....if they are making those tanks like the "old school" ones were made, then they are truely under 2" in diameter.
The "old school" 7oz. tanks, and long 10oz. tanks, are really under 2" (like 1.95")...basically, they are long 3.5oz. tanks. Modern 9oz. tanks are running 2.1 to 2.14"" (guess we just ignore the extra 1/10th inch, even if it puts us on the wrong side of the "2 inch/2 foot" rule). Slap a couple of decals on a bare modern 9oz., and it will be about 2.2".