No, I do not. It fits me well enough as it is, but perhaps some of what you know can get it to fit even better.
All you have to do is get the hat wet and then shape it around your head, then let it dry. A tight weave might take more water than the loose straw hats I use for gardening.
Oh, wait. You have a high dollar hat, it probably has a sewn in sweat band. If so, disregard the above and look for you-tube videos. I know that it can be done, one of the joys of straw hats is how easy they are to custom fit, but none of mine have had inner sweat bands before I sewed a ribbon around the inside.