This is the stuff I bought, it has a high moly content.
https://www.google.co.uk/search?newwindow=1&sxsrf=ALeKk00WqzFpwAwcrJCJOSDqXf078gQBNw%3A1606726390208&source=hp&ei=9rLEX82TCoeWa6yFueAM&q=Honda+M-77+Assembly+paste&oq=Honda+M-77+Assembly+paste&gs_lcp=CgZwc3ktYWIQAzIECCMQJzIHCAAQyQMQCjIECAAQCjIECAAQCjoECAAQQzoLCC4QxwEQrwEQkQI6CgguEMcBEKMCEEM6DgguELEDEIMBEMcBEKMCOggIABCxAxCDAToOCC4QxwEQrwEQyQMQkQI6DQguELEDEMcBEKMCEEM6BwgAELEDEEM6BQgAEJECOgUIABCxAzoCCAA6BwgAELEDEAo6CggAEMkDEBQQhwI6BggAEBYQHjoICAAQFhAKEB5QngpY3WVgk2hoAHAAeACAAZIGiAHNL5IBDDEuMTAuOC41LjYtMZgBAKABAaoBB2d3cy13aXo&sclient=psy-ab&ved=0ahUKEwjN5vKd8qntAhUHyxoKHaxCDswQ4dUDCAk&uact=5
Available on Ebay, not cheap but good.
https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=Honda+M-77+assembly+paste&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=Honda+M-77
Beware of others with a low Moly content.
Information is a bit sketchy but from what I can find Castrol Moly grease is about 6% Moly and the M-77 is 60% Moly.