I think there are probably a couple of reasons for this - the most obvious is that I'm more attuned to Thirkell's sense of humour now that I'm more familiar with her, she can be quite subtle so it's easy to miss bits first time round. The second reason is that I've read more around her since I first read these books. I now recognize the Trollope references along with some of the others, and am better at recognizing when something probably is a reference all of which adds layers to her writing. It possibly also helps that I'm now in the best part of the series - I haven't read any of the later books but am told they become increasingly formulaic, the very early ones have a tendency to a casual antisemitism that I find disconcerting but that seems to crop up less as the books go on.
I imagine somebody somewhere must have researched this but it's a curious thing observing how general attitudes change towards Jewishness in middle brow fiction. I'm reading Zola at the moment and he's having a sly dig at attitudes in France. Most Victorian writers I've read have displayed what was clearly a common prejudice and this continues well into the 1930's but from my reading I would guess it suddenly becomes less acceptable, less politically correct perhaps, as those uncomfortable references start to disappear.
There is also a particular poignancy to the pre war books - this is a world of comfortable middle class living which would never exist again; servants are plentiful, standards are set, and the world seems a uniquely secure place for these characters full of comfortable certainties and afternoon tea on the lawn. Plot wise not so very much happens, young Colin Keith is training to be a barrister but wants some financial independence from his father so takes a job as a junior master at a local school. There is plenty of discussion about boys - also poignant - boys like this may still exist in the grandest private schools but mostly they have turned into teenagers which on the whole doesn't sound like much of an improvement. There is also the obligatory romance and a fair amount of humour booth of which are extremely satisfactory but what makes Thirkell special and worth being reprinted and reread are her occasional moments of observation and insight.
The one I've bookmarked in 'Summer Half' is a bit about blackshirts, it's only a couple of paragraphs but it jumped out at me. The phenomenally shallow Rose Birkett has been to the cinema with a couple of brothers (Fairweather Senior and Junior who are, I believe, on leave from the Navy) and they're recounting a something they found funny...
"Oh yes, that was awfully funny,' said Fairweather Junior. 'It was a man selling little books. One of those blackshirt fellows, you know like Puss in Boots in a polo jersey. I don't know why, but it was awfully funny. Lord! It was funny!' he added breaking into laughter again.It's not much but it says a lot about attitudes in Britain in around 1936 (the book was originally published in 1937) and about Thirkell's attitude inparticular. Fascism may have been alright for the lower orders and a few eccentric aristocrats but for decent middle class people it clearly wasn't the done thing. The earnestness of young communists is mocked in a friendly way in the assumption that they'll grow out of it but at least it has a sort of drawing room respectability.
'I'll tell you another funny thing about those blackshirts,' said Lydia. 'No one knows who they are, or where they go. I mean, have you ever seen one, except standing on the pavement in waders, looking a bit seedy? You meet quite a lot of communists and things in people's houses...But you never go to tea with someone and find them sitting there in their boots."