On German Ebay. I would certainly bid on it if it was a 7! Seems to be in pristine condition. Tall straight crown, center dent. 1930s or possibly even 1920s?
http://www.ebay.de/itm/alter-Herrenhut-grau-Homburger-Hut-30er-40er-50er-Jahre-Vintage-Mode-/310621836931#ht_500wt_1413
http://www.ebay.de/itm/alter-Herrenhut-grau-Homburger-Hut-30er-40er-50er-Jahre-Vintage-Mode-/310621836931#ht_500wt_1413