No and it doesn't make much sense to anyone who understands the combustion process. Oil has a much lower combution point than the type of lead added to gasoline. The "oil mist" would just partially burn and coke up the combustion chamber and exhaust system in a simular way that oil does in two stroke gas and diesel engines. On gas engines oil is mixed with the fuel and on diesel (and some gas) it is due to port leakage.

There are lead substitutes for sale at most auto parts stores. I have no experience with any of them.

Would look pretty could as a period "Snake oyl" piece though.

Having inspected thousands of internal combustion engines, there is nothing that can fix worn out parts except good machine work.

Best advice I can offer is to run it until the valve leakage is unacceptable and then have hardend seat installed.

Jim

Good luck with your project!