Mike Haseler commented
>However, John raised an interesting point about whether references to
sexual anatomy were or were not seen as "crude" (lewd, vulgar).<
Given Carol's drawing attention to Old English riddles - which were clearly intended to give the listeners something to snigger about - and the euphemisms discussed in Robert Frank's "Sex in the Dictionary of Old English", which you referred us to, Mike, I'm having second thoughts.
It looks as if certain words were indeed thought unsuitable for writing down (which doesn't tell us how and in what circumstances they were used in speech). And since conventional dictionaries reflect the written language (the Dictionary of Old English doesn't include a word if it never appeared in an Anglo-Saxon original text) that makes your search for 'crude language' difficult, Mike.
Mike Weatherley - I'm not sure that modern writers' or film-makers' concepts of ancient 'bad language' are reliable! The content and nature of 'swearing' certainly seems to have changed over time. See Geoffrey Hughes' book _Swearing: A Social History of Foul Language, Oaths and Profanity in English_ or even Robert Graves _Lars Porsena: On the Future of Swearing_ .
The man Shakespeare called a 'scurvy whoreson rogue' would probably be called a 'f***ing c***' today.