Put orange rind in a half-pint jar with 1/4 cup vodka. Seal it and shake occasionally. Let it steep overnight. -- Pour sugar and 1 2/3 cups vodka into a 28 ounce bottle. Seal it and shake until all the sugar is dissolved, then add the maple syrup. -- Filter the orange extract through a fine handkerchief or coffee filter until it becomes clear. -- Add a tablespoon of the final extract to the vodka syrup mixture and mix well. If your orange peels are much more or less aromatic than average, adjust the quantity so that you have enough to hide the maple flavor, without having enough to make the liqueur bitter or recognizably orange flavored.