Looks like yours could be unique to the electronic ignition mounted to it, and so may not facilitate other systems as straight bolt on fit.
You've probably got to go with another plate from that supply line (ok) to get you back to std.
Your advance retard mechanism seems to be still fitted (can be seen peeping through top hole in plate) which you'll need to use. Looks like the electronic chopper disc is fitted to the A&R mechanism. Worthwhile dismantling that and putting up a photo to see if any bits are missing.