Here are some images of the framing process including the raised floor to compensate for the 5” drop within 4 feet. That’s a lot of custom cut floor joists!
Fire blocking was added to the tops of the framing since this is a balloon style home where fires were known to start on the bottom floors and travel though the walls extremely quickly because they we all open from basement to roof line.
Some PL Adhesive before the 3/4” plywood subfloor went in. The expandable foam was used to fill in the cracks between the original floor boards.