OMG you didn't! Just kidding I remember that point. Looks like you've got an awesome place to work on her as well.
Looks like you kept the wood to use as templates, very good! I had to estimate some of the curves since there was a bunch in the back rotten out.
A few lessons learned.
Replace the plywood with something that has at least one A face placed up so you'll have a nice smooth floor.
You can paint the entire top of the floor with porch&floor paint. Leave the underside unpainted so moisture has a way to escape if it does get wet.
Assuming you're not going to insulate the belly with fiberglass, don't do it. The fiberglass originally got sandwiched between the floor and metal framing, easy to install that way, but it also helped prevent floor squeak. Place a bead of polyurethane sealant/adhesive on top of the frame/outriggers then lower the new floor directly down onto it when reinstalling.
The very front and rear pieces of plywood have the U channel that just sits on top vs the C channel that wraps the edges of the wood. On those sections I tightly wrapped the entire edge and in from the edge about 1.5" in several layers of aluminum metal tape. To protect the edges from water/moisture.
For bolts when the time comes, consider grade 8, steel cap screws(bolts) nuts and washers, that have armor coating on them. They are VERY corrosion resistant, so shouldn't rust away for the next 30+ years. Plus not bad priced online at McMaster Carr.
Best wishes for a smooth project.