its working for me for the same client (although it crashed after showing the sprite - but i think it was an issue with the sprite i used).
You need to edit weapontable.lua
1) In Weapon_IDs table add your entry. for e.g. i added Oriental Sword (last entry was for Wizardy Staff which is 97. so i used 98.
this is also the classNum value you need to specify in ItemInfo.lua
WEAPONTYPE_Oriental_Sword = 98,
2) Next in WeaponNameTable add your sprite suffix.
Code:
[Weapon_IDs.WEAPONTYPE_Oriental_Sword] = "_Oriental"
3) Next in Expansion_Weapon_IDs map the custom to a weapon type . mine was a 1-H sword so
Code:
[Weapon_IDs.WEAPONTYPE_Oriental_Sword] = Weapon_IDs.WPCLASS_WEAPONTYPE_SWORD
as for view id in item db it is like what is said in the wiki (0-30); i dont think client even checks that value.