I'm in the Northwest part - Valparaiso.
Attaching the floor: The plywood in front was "mostly" fine - so I didn't pull it. I just laid more on top to beef it up and smooth it out. Laid plywood on top of the fiberglass bottom in the back half. There's a distinct seam in the floor of different heights. Seems to have been that way originally in this trailer. Very odd.
Anyway, I attached to the plywood using construction adhesive - no bolts. In the front - it was construction adhesive plus some wood screws into the old plywood.
Rate of progress has been VERY slow. Various reasons for it. Camping trips with the kids - visiting with Grandma - work on the house - work. All took priority. What I've done lately has just been to start rewiring the running lights
. New plus - all new wires - new lights
everywhere. Still have to finish all that and test it before I start filling in the interior.