"...if I had Blunderbuss Hall here, I could show you a range of ancestry, in the O'Trigger line, that would furnish the new room; every one of whom had killed his man! For though the mansion-house and dirty acres have slipped through my fingers, I thank heaven our honor and the family-pictures area as fresh as ever."

Questions:

Are Blunderbuss hall and the mansion-house the same thing? It sounds not, because he's saying if he had it there to show Bob.

Has he lost both Blunderbuss hall and the mansion house if their two distinct places?

What new rooms?