Well I am making progress on my restoration at least as far as the main unit and disk drive - spoiler alert - it was faulty RAM chips... I can now boot HDOS 1.5 but, you will need to wait for part 2 for that and what was involved.
https://youtu.be/QD1V3uBg4Iw
Hopefully the background on the system and its UK availability will interest some readers.