Technical Ac plenum door foam

I posted a thread on this yesterday but can't find it now. Went to my profile and "my content" even and can't even find it there.
I'm adding "factory AC" to a truck that originally came without.
I wound up with 3 heater boxes for a truck Luke mine with A/C and I'm building 1 good box from all of the best parts a**** the 3.
On all of them the foam in the "recirc" door is flaking away and basically shot. On all 3 boxes also the foam on each of the other 2 doors within, is fine. The metal door itself that the foam attaches to is fine. What kind and where can I get the right kind of foam sheet to rebuild these doors?

 

McMaster-Carr

https://www.mcmaster.com/products/foam/

But you will need to figure out what foam you need.

 

You could try an outfit like vintage air, they might tell you what to use or even sell you some