6 o'clock position in Lighthalzen
-- 1887z and the following: --
Tassel x 1887
Bucket Hat  x 1
Magnifier x 10
Renown Detective's Cap 
|Cost: 1,887 zeny
In the menu options, you just have to believe that he is Morris Poe and he will tell you about the items you need for the hat. The following seems to work.
You have to first ask him 'Who are you?', then tell him I've never heard of you.. When he mention he is the famous detective Morris Poe, you just have to pretend to be surprised and answer Golly, Morris Poe?!.
Airship to Yuno, Hugel, Einbroch, Rachel & Lighthalzen