Nuke TibEd from your PC as it is well sucks.... You can do everything and more in notepad/wordpad.
In TS the cameo for each unit is set in the art.ini (aifs.ini for firestorm).
In the stock art.ini you will find
[4TNK]
Voxel=yes
Remapable=yes
PrimaryFireFLH=40,32,96
SecondaryFireFLH=-32,80,120
PBarrelLength=192
Whay you want to do is add Cameo=*File_Name* to the [4TNK] data. At the *File_Name* part add the name of your Cameo with OUT the .shp When done you should have somthing like this.
[4TNK]
Cameo=4TNKICON
Voxel=yes
Remapable=yes
PrimaryFireFLH=40,32,96
SecondaryFireFLH=-32,80,120
PBarrelLength=192