It is possible to convert the Magnette so that it runs on negative earth and uses an alternator to provide superior output and charging capabilities. This is useful if you want to fit additional powerful light units or good hi-fi (which generally only works with negative earth). This documentprovided courtesy of Moss Motors is written with the MGA and early MGB in mind but the principles hold good.
If you want to retain the look of the original control box you can get one designed for this conversion that looks like the original but is internally wired to make the right replacement connections, has a fuse and works the ignition light. This looks the part and is identical to the original control box. Part no. 080.971 from Holden Vintage & classic.