FYI that is the old style ebox used till 1980. they are hard to find but the new style box will work. the difference is that the old one has a cdi and a coil the new one uses a combined cdi/coil they call an igniter. also the battery starter wires are connected on the outside of the ebox and the start/stop switch wires are probably a little different.
the only problem you may have is that the trigger coil on the older stator has a different resestace spec. so you may have to change the stator too if you use the newer ebox but i am not sure.