If there were non-resistor platinum plugs available for M103 and other Merc engines of the era whose ignition systems are specifically designed for non-resistor plugs there would be no issue, but the heavily advertised and widely available "Bosch Platinum" spark plugs are only available in resistor type, and resistor versus non-resistor remains the fundamental issue.

All the redundant ground electrodes on the multielectrode versions are also a major issue and further reason not to use these plugs.

Duke