I got me diameters and me perimiters muxed-ip.... but even now, had to get M to correct my perimiter into a circumference... and you don't want to see all the typos that I've had to correct just trying to say that...
Got a couple of pics!
The clear bottle has a diameter of ~ 4", circumference of 12 and an 'alf inches. That's the bit that makes me wonder about a mould. But it is the only bit I've seen (or have) with this tapered bottom.