Thanks Richard for the suggestion.
I’ve located the Course Computer – stbd side behind the main switch panel, it is quite a bit larger than I thought. Also now know that the Sea Talk splitter is located stbd side behind the E80 MFD.
I found some wiring anomolies, e.g. why is the only the NMEA in connected at the VHF, the NMEA out wires are cut-off short ? I will now give RAymarine Customer Support a call to try to get some answers 🙂