I now know why the valve covers were so dirty yet the internal engine parts were so much cleaner. Apparently, the previous owner used to drive long distance regularly so the annual mileage was high but only changed the eng oil like once a year. So, just circulated ...
In the meantime, just keep removing the parts and cleaning, cleaning, cleaning...... All four cam shafts removed and rocker arms exposed. Still not cleaned ...
Bit of drama updating the firmware of my trusted wireless router from ASUS resulting in loosing part of the 5GHz wireless channels and very slow access but erasing the nvram worked well and now back in business. Several parts arrived from Japan and Honda UK. ...