This is my 4e guide to oriental adventures item conversion. Pretty much all of the items needed are already in the game its just figuring out what item is what in terms of an oriental game.
Weapons:
Tanto -> Dagger
Short Sword -> Wakizashi
Bastard Sword -> Dueling Katana
Greatsword -> Katana war sword
Fullblade -> Nodachi
Lotulis -> Lajatang or Korobokuru Lajatang
Spiked Chain -> Kau Sin Ke
Spiked Gauntlet -> Nekode
Dragon Paw -> Sang kauw
Simple Weapons—Ranged
Blowgun -> Blowgun
Martial Weapons—Melee
Small
Wakizashi -> Shortsword *
Large
Nagamaki -> Falcion
Naginata -> Glaive
Exotic Weapons—Melee
Tiny
Nekode -> Spiked Gauntlet
Tail spikes -> Type of Shuriken
Small
Butterfly swordΔ
Jitte
Ninja-to -> Shortsword
Sai
Tonfa
War fan
Medium-size
Katana -> Bastard Sword if fencing sword
Greatsword if war sword
Kau sin ke Δ -> Spiked CHain
KawanagaΔ -> Alhulak
Bludgeoning
Lajatang, korobokuru Δ -> Lotulis
Large
Chain
Chijiriki
Bludgeoning
Kusari-gama
Bludgeoning
Lajatang Δ
Sang kauw Δ
Sasumata
Shikomi-zue
Sodegarami
Three-section staff Δ
Tiny
Fukimi-Bari* Δ (Mouth Darts)
Small
Chakram Δ
