ok, i tried using someone else's custom weapon (not mine) to test this, & it goes like this (sorry, i don't know how to upload pictures):
data\sprite\¾ÆÀÌÅÛ\Dorcus.act
data\sprite\¾ÆÀÌÅÛ\Dorcus.spr
data\sprite\Àΰ£Á·\¸ùÅ©\¸ùÅ©_¿©_1849.act
data\sprite\Àΰ£Á·\¸ùÅ©\¸ùÅ©_¿©_1849.spr
data\sprite\Àΰ£Á·\¸ùÅ©\¸ùÅ©_³²_1849.act
data\sprite\Àΰ£Á·\¸ùÅ©\¸ùÅ©_³²_1849.spr
data\texture\À¯ÀúÀÎÅÍÆäÀ̽º\collection\Dorcus.bmp
data\texture\À¯ÀúÀÎÅÍÆäÀ̽º\item\Dorcus.bmp
(in item_db2.txt)
1849,Dorcus,Dorcus,4,10,,40,200,,1,4,0x00008000,2,2,2,4,110,1,12,{},{},{}
when i played it, the item is there, but when i tried to equip it, my game crashed.
i got the weapon from this site (http://www.usamimi.info/~saecreate/?cat=9&paged=1), its a claw/knuckle called Dorcus.