Thanks very much IvyKaty! That's a very helpful tip about finding everyone's parish in the census and using that to work backwards - I've been collecting their parishes but didn't make the connection with the parish registers. I'll run through all of those next.
I've actually taken a leap forward since posting this as another post on this board directed me to RootsChat, which directed me to a local history society page, which turns out to have digitised the parish records for the county between 1801 and 1837. So suddenly I have a whole load of extra information!
It's really house history, but I thought I'd try and do a reasonable description of each family to live in the house - names, ages, professions etc, and a little about their life story.