Thank you for your suggestion.
Without going into detail the 125H uses a Lambretta/Vespa type flywheel ignition, within the generator rotor. Yes, the trigger coil is inductive and is supposed to produce a full waveform. This was part of my problem, because mine didn't produce a full wave form and therefore didn't advance the ignition. However, since replacing the trigger coil and using 3 different trigger coils, there is no ignition advance. All of the other components have been passively and dynamically tested and appear to be functioning correctly. So, it appears that the interaction, or lack of it, between the generator rotor and trigger coil appears to be the problem. Ducati Electronnica components greater than 30 years old appear to be the problem and OME replacements are no longer available. At present there are no alternative ignition systems manufactured to replace the OME and having contacted all potential manufacturers and received polite "Not worth the time and effort.", my thoughts are turning to alternative engines!
If your interested in the saga so far, here is the link to the thread on the Morini Riders Club forum: MRC_MM125H_ignition_no_spark!
Good health, Bill