It's a shame the enlarged version of the band doesn't actually match the one worn by Matt Smith :confused
- My mistake it actually does
It does match, but they have reshaped the bangs (the curls at the side) a little on Smith's hat upward a little.
Reshaping the brim of a stetson is relatively simple, but to do so you should make sure your hat is capable of shrinking a little and still able to fit. You can reshape a brim many times using this simple method to as much or as little as you like.
Step 1) Boil a kettle of water.
2) Hold your hat so that your thumbs are in the inside of the curve.
3) Hold the brim over the steam of the kettle until it starts to go soft and then use your index fingers to push up or down on the brim (depending on how you want to go, smiths is up a bit).
4) repeat on the other side. The best way to get a match is to use your eye's judgement.
And, as always, make sure it's a genuine Stetson™
Best way to measure your head is to use a tailor's floppy measure in cm (not inches). Whatever size your head is (M, S, L) will translate to all the other regional equivalents. (In my experience a medium from the US fits exactly the same as a UK or EU medium size).
I also own this hat (did before Smith did). And others.