I've got a new 10e. Ya might be able to get the OEM foam direct from Pelican?
What I'm gonna do with mine is pull the staples out that hold the top n bottom together and use two part foam to fill in the entire bottom of the boat, then cut it level and run wiring on top of it (in the top half) before sealing it back up. Yeah it'll add weight to the boat, but it'll add ALOT more buoyancy which I need since making a 54" long and 43" wide casting deck for the bow.