Bill,
I know what you mean about pouring in wind. In my hangar where I normally fuel it is not a problem. For trips if it is going to be windy I put the oil in used pint-size plastic bottles of Marvel Mystery oil. They have a long neck with a narrow opening that is easy to put a finger over. I hold my finger over the top until it is below the opening of the fuel tank. Then the small opening allows it to come out at a rate that is not too fast in case you don't want to use the whole bottle.
Dave Leonard