Welcome to the new Wizard Outboard Forum.
Use 2 cycle TCW-III oil at 1 cup oil to 1 gallon of regular gas. It mixes easily and burns cleaner.
The original spec was non-detergent 30wt oil. Although correct, it will carbon up your motor over time. Modern TCW3 oil is more than fine to be using on a motor of that vintage, and that is what I would recommend using. JP