The only floor board that was springy was the one furthest forward in between the pass thru. I did not glass over the top I removed the panel and removed the bottom of it because I could tell the wood was rotten see the pictures in post # 2 and 3. The wood was all rotted so I removed it all and put new wood inside and fiber glassed over that several layers until it felt solid. I kept turning it top side down to the ground and walked on it until it felt solid.
I guess if I could give you some advice is that the sides are sort of beveled to match the tray it fit in, try to get it to fit in the best you can, and so there are no gaps when you put the board in the tray, mix up a good batch of resin and pour it in to secure the wood and fill any gaps there maybe under neath where the wood meets the top of the tray, it will ooze out the edges but from what I could tell this was a good thing just clean as you go it will give the best fit and then put something on top of the board while the resin drys. I let that dry for a day or two before I started to lay fiberglass on top and seal the edges as best you can. Sand between each layer of fiberglass. For the fiber glass I just followed the directions on the bottle.
I took several days letting the layers dry was not in a hurry and had other stuff to do while it was drying.
I never used fiber glass before this and I didn't find that it was too difficult, if anything a little messy and took some time to get it all done but again I wasn't in a big hurry.
Get lots of gloves as it tends to get messy. Other than the resin and fiber glass I used some old disposable bowls for mixing and get several cheap disposable chip paint brushes, home depot or lowes has them for like .49 cents gonna use several of them unless you clean them between each layer.
To remove the wood I removed the panel cut out all the old wood with chisels and razor blades with a scraper and then sanded it smooth when it was almost all out.
For the last layer to cover the fiber glass top layer as you can see in post # 5 I used some of the Flex Seal as seen on TV just because I had a can laying around so that it was black and sealed the edges but I doubt it was necessary.
The other two panels if they are springy I did not take them apart because mine were in good shape, I think the other panel where the ski pole goes through seems to be the same process, but the one rear of the engine does not seem to have any wood in it as far as I could tell.
Good luck with your project let me know if I missed anything.