I have access to the inside, but its very tight. Probably have to use a caulking gun to get anything back there. I think i will try the washers/nuts thing. Thanks.
Okay, then instead do this... repair it the same way we did, except*...
Get a 2" or longer bolt, can be zinc.
2 nuts, a *fender washer, additional hardware as you see fit, must all be stainless (you may need to grind a side of the fender washer for the pump tunner)
Cut the head off long bolt, Wax this bolt
Clean the nuts and washers with Acetone
Clean the hull with acetone
On the non-cut end, put on a nut, the fender washer, another nut
Lightly tightened, make sure you can remove the bolt without any tools on the hardware
Wax the ride plate
*Feed a guide wire through the hole into the engine compartment
Pull the stud end through the hole
Use your glues to secure it in place (I'd use epoxy with cabosil, but use what you please)
--- Nuts and washer need to be throughly covered so they wont spin, reinforce w/ glass if possible
Put a single layer of 10oz or lighter cloth over the stud
Use the remaining 3 inserts to tighten down the rideplate to the hull, compressing the glass and ensure the stud is in the right place and square
Add additional material as you see fit inside
Allow to fully cure
Remove the ride plate
remove the stud with vice grips
Remember, you are going to need to hold the new insert in place. ours pushed against the foam inside. You could clean up the thread on the cut bolt so you can add a nut from that end. Then tighten the extra bolt against the ride plate since you will have a fender washer to keep it from pulling through the hull.