The scrimshawer definitely has some weird things going on. I'll admit that I've been away from DF for a little while, so I may be not perfectly helpful on this, but here's what I'm seeing as problems:
Craft Bone Sword: I don't actually see a sword in the kobold item list at all. There IS a training machete so the idea is probably to have a machete.
Craft Bone Spear: Spears have been replaced with pointy sticks, so I believe the code could be replaced as follows
[REACTION:CRAFT_BONE_SPEAR]
[NAME:craft bone short spear]
[BUILDING:SCRIMSHAWER:CUSTOM_P]
[REAGENT:A:1:NONE:NONE:NONE:NONE]
[ANY_BONE_MATERIAL]
[USE_BODY_COMPONENT]
[PRODUCT:100:1:WEAPON:ITEM_WEAPON_POINTY_STICK:GET_MATERIAL_FROM_REAGENT:A:NONE]
[SKILL:BONECARVE]
Craft Bone Dagger: Same issue as the machete, we've got a training dagger but no actual dagger.
Craft Bone/Shell Hammer: There also isn't a bone/shell hammer under item_kobold, though there are bone throwing hammers which don't appear to be listed as a kobold reaction.
Craft Bone Chopper: Choppers appear to be incorrectly referenced as ITEM_WEAPON_AXE_CHOPPERS.
[REACTION:CRAFT_BONE_CHOPPER]
[NAME:craft bone chopper]
[BUILDING:SCRIMSHAWER:CUSTOM_C]
[REAGENT:A:1:NONE:NONE:NONE:NONE]
[ANY_BONE_MATERIAL]
[USE_BODY_COMPONENT]
[PRODUCT:100:1:WEAPON:ITEM_WEAPON_CHOPPER:GET_MATERIAL_FROM_REAGENT:A:NONE]
[SKILL:BONECARVE]
Craft Bone Shovel: Looks to be in order to me!
I'm not sure about ranged weapons (as I was pretty much just looking at the basic melee bone weapons) but I think those are the major scrimshawer problems. I'm not sure if this is the case in game, but I'm also noticing that item_kobold has a banded skirt, shin guards, and a shield, but no chest armor. That also could be a matter of design choice. If there is anything I can help with for Kobold Camp, please let me know! I'm trying to get back into playing and would be happy to assist
Also, I was planning on looking at the kobold items to add in interesting attack-descriptions there (definitely for my own amusement, possibly to offer if KC or Masterwork wanted them), but don't yet know what the strings mean. I'm sure you both have more important things to do, but I'll let you know if I come up with anything!