Rubber material on truck bed

Inlet, I bought my 650 because it is light(2000 lbs), and it doesn't extend beyond the bumper making parking in downtowns a breeze. Your locating the camper back creates a larger opening in the bed for water to enter and transfers more of the 2000lbs. behind the rear axle on a short bed truck. I made a 1/2" plywood platform base that covers most of the truck bed, then 3/4" plywood one ft. wide the length of the camper under the camper box's narrow 3/4" aluminum frame rails-total height 1/2 +3/4=1 1/4". Cut out the last 6" x 46" for the plumping.

Try a concrete plant , gravel pit , grainery , etc. , they often use heavy rubber belting to run the conveyors . They usually have some broken scraps they will give you .

I've lifted the camper box one inch up off the truck bed so the drain valves located in the last six inches of the bed don't get crushed. I've built a wood frame that laps 2 inches in, and 2 inches outside of the perimeter of the camper box. The drain valves and hose attachment come off the tanks facing the back of the truck bed and can't be relocated. I think my best option is rubber glued to the wood frame. Where do I find a 3 inch wide, 1/4" thick roll of hard rubber?

My Lance dealer was going to mount the 650 ....4 inches to the rear of the box so the cleanouts would clear of the bottom back of the bed. That would be on a 6 ft 6 inch Silverado bed...Would that work for your Ford ?

Just curious, I read you were shimming the camper back away from bulkhead?

I would paint the plywood and screw it to the bottom of the camper then get a rubber truck bed mat and set the camper on that, Is there a way to reroot the lines to come out the side of the camper?

I would advice rubber.
When plywood is softer than metal and it wear out itself not the bed,
the paint is softer than plywood and will look pretty bad after some time.