Much to my amusement, I've just spent the afternoon reading The Thursday Kidnapping (I bought one of the Badgers Book copies advertised, in anticipation of a re-read and because I'm a completist) and there actually is a Terrible Tweedy Type (actually, she's got an interesting backstory, especially that the Big House in Devonshire from which she sprang has got bigger in memory over the intervening four or five decades) called Miss Lambert who does say, "Down, sir! Down, sir!" to a somewhat excitable spaniel, so it's perfectly Forest and perfectly Landed Gentry in Forest as a usage.