Quoting Steve Engledow steve@iffirewouldfall.com:
#header a:hover { some nubbins }
...is that what you mean?
It most certainly is, and it has an effect. Sadly, though the answer was spot on, my question was wrong!
It turns out that the link in question is the title of the page, and so is set as <h1> and it is *that* which is over-riding the other stuff.
So can I set anchor attributes within the <h1> definition?