I was left wondering if Ryder's daughter was indeed his child, given the references he made to his wife having had an affair, and that they had parted when he went to South America with her in tears. I didn't get the impression that that was because she was upset to see him go.
As for Brideshead, it definitely had been left to Julia because the estate wasn't entailed (i.e. it didn't automatically go to the eldest son) but what on earth she was to do with it, who knows! I think the debts were resolved by selling Marchmain House, in London.
I must admit I read
Sword of Honour a very long time ago, and don't remember it as clearly as some of his other books, so you could well be spot on there, Lynx-lynx!
I have read the first three books of
A Dance to the Music of Time and keep planning on reading the other nine this year. Somehow half the year is over already!
No, I haven't ever got into Mitford - another on the frighteningly long list of TBRs.