Exactly. Just copy the file and change the coordinates in the holes section and the size of the enclosure in the sides section. For example here's what I have for the Spirit Box:
sides = [
["A", [66.16, 121.21]],
["B", [66.16, 35]],
["C", [35, 121.21]],
["D", [66.16, 35]],
["E"...