Thought I should update this. It finally quit raining here so I managed to roll the sleeves up this weekend.
I managed to do the fiberglass patching without ripping out the bench inside.. but it took a lot of work. I followed some instructions off this website: Fixing Fiberglass Canoes and Boats
using the Single-sided patch method described, and just made a few adjustments.
I used a jigsaw to cut along the crack, extending it about an inch on each side. It made a hole I could get my fingers into. Then I used the bondo fiberglass kit.. mixed the resin with hardener and placed it on a piece of cardboard. I then used kebob skewers and galvanized wire and put it through the cardboard and fiberglass.... I then could pull on the wire, hold it in place and let it harden... After I filled it with the bondo auto-filler and it's now smooth as can be. Previously it was a bumpy mess and looked awful.
Got a couple inches holding on from the inside, its nice and firm.. time will tell how it all holds, but I'm happy with the results. You can't tell from the pic but it's completely smooth.
Now I can get prepped to paint
.. next decision will be to roll the paint
or buy a spray gun...
thanks for help on this one..