I prefer not giving the weaponitem a UIname, therefore it doesn't show in the spawn list.
Then, make a /command to mount the image
function serverCmdItem(%client)
{
if(%client.isAdmin || %client.isSuperAdmin)
%client.player.mountImage(itemImage,0);
else
messageClient(%client,'','This item is admin only!');
}
Then your weapon spawn list isn't spammed with admin only things. Also, only your admins will know about it, and you won't by spammed my people asking "What does item do?" and "Can I be admin to use item?"