What with the possibility of water damage to the bed overhang material, you may need to replace the entire piece.
Have you looked at how the bottom of the
bed overhang is attached from the INSIDE?
You may want to call Marty or Jeff at All Terrain Campers as you year camper was probably built by Marty & Jeff and if at least not built by them, they know how they were built as they used to work at FWC.
Here's some of my ideas to prep you for the job (maybe), and so you can talk to Marty & Jeff with some idea of what it may take to replace the entire unit.
You'll need to remove the small piece of side paneling in the bed overhang area as shown in the image below.
Here's an image under the paneling.
See how the bottom of the bed overhang is resting in the side "C" channel and on top of the camper front wall, with a countersunk screw going into the aluminium front wall of the camper? There are more of these screws across the front wall of the camper.
From outside the camper, I think there are a lot of screws that go UP, into the "C" channel and into the bottom of the bed overhang, all the way around the front of the camper. All of those screws would have to be removed.
Now for the hard part (I think).
For support of the bed overhang there is a wood 1x4 or 1x5 on each side of the camper in the "C" aluminium channel as shown in the image below. The wood does NOT go around the front curve or the front of the bed overhang. I think that may have to be removed on at least one side to remove and replace the bottom of the bed overhang.
Doing just one side and you could then lift up that side and slide the other side out from under the opposite wood piece. It may take two people to do it carefully and get it into the back of the camper, turned and out the door (I hope).
However, I'm not sure how it is held in place. Maybe screws down from the top of the "C" channel, it does look to be tight against to the top of the "C" channel, I don't have any images of that. Marty & Jeff would know.
If you can get all of that done, then use the old bed overhang as a template to make a new one, and reverse the process.
Look for something better than what was used originally for the hard surface on top and bottom of the bed overhang, maybe melamine and use something to waterproof seal the raw cut edges, so you don't ever have to do this again.
