Watching British ghost stories on Youtube has paid dividends. Not only have I found leads to trace a memory from the 1830s, but tonight found the manor house I remembered, and it was NOT in the era I thought!
It turns out, West Wycombe Park is the best match. The stately house and gardens was built starting around 1740 and work continued for some years. Unless there is another stately home situated near the bottom of a hill exactly like this one, this is the house I saw:
The gray building you see on the hill behind this manor wasn’t there in my memory; it’s a mausoleum that was built around 1764. So that puts my memory from between 1740 and 1764. Also, the interiors are colorful, airy, and Georgian and look nothing like my flashes from a Tudor life, so I’m doubtful that these memories have anything to do with each ther.
I had the impression that I was a young woman, but later impressions (from the American Revolution) have me as a grown man; I must not have had a very long life in this place.