Okay so these items are a bit messed up.
Equipping model training hat BY ITSELF gives
2 def/2 dex. According to RMS this is correct. According to the item description, it's supposed to give 5 def. So the item description is probably wrong.
Equipping well chewed pencil BY ITSELF gives
7 hit/2 dex. According to the description it should be giving me 3 hit only, since I don't have model training hat.
Equipping BOTH gives me
4 dex/9 hit/2 def.
It should be giving 4 dex, 7 hit (4 of which come from dex), and 4 def (or 7 if you go by what the description is on our server which I think is wrong).