What are your plans for this find? Spin a prop and make some wind? The end result will determine how much time/effort you want to exert. If your plan is to say I have an airplane engine want to see it run then only 3 things are required, spark, air and fuel.
Why does it need to be overhauled? Does it turn over by hand? Is it complete? What is your mechanical back ground?
Not enough info to advise.