Finally found some over here, £18 inc postage for 75g tube:
https://h-tune.co.uk/genuine-honda-molykote-m-77-assembly-paste-75g/
https://h-tune.co.uk/genuine-honda-molykote-m-77-assembly-paste-75g/
Sounds like the previous owner of my bike toI know but I'm finding that the previous owner didn't really do maintenance or anything else.
The tyres are 24yrs old, the air filters are powder, so I'm going to go through everything as recommended here.