Nijalninja,
Get a wooden stick or dowel and pulverize the end of it. Soak it in kerosene for a minute or more until it acts as a wick and then light it on fire.
You can then use the soot to blacken your parts and then get a good transfer of fit to the wood.
A light spray or wipe of some sort of oil to metal will allow the smudge to attach to the parts for in- letting black substitute.