I have a Femsa that Bert Neville at Small Coil Rewinds built a type of CDI box for so that I could then run a Japanese coil. I now run an RZ Yamaha twin plug coil on my Mk7 360. It has been totally reliable for the last 12 years, idles better and rev's better.
I would imagine they could build the same for a Motoplat coil replacement. As long as yours is a electronic type system, not points.
There business is at 50 Edols St, North Geelong.
Stan.