Thanks for your considered reply.
I take your point with the many themes.

I am a happy camper
great work - thx

I see in 'Personal Settings' - Allow comments to this entry y/n
This works for posts after setting 'N' but still displays the comment div with all the content - except the form.

The FAQ suggests editing the templates/{THEME}/entries.tpl and it was not so difficult to find <div class="serendipity ...