Foam

Working on my 85 d150. Adding ac to a truck that came from the factory without.
I have 3 factory ac plenum boxes apart. All have bad foam on the recirc door. Other doors within are fine.
I found a PN for the original recirc door, but every place I look it shows "discontinued".
What kind of foam can I use to replace the original?
Plan is to scrape what little remains of the original foam and glue on some replacement.
The door itself (metal) behind the foam seems solid.
I did have to pry them all out, were all stuck at bottom pivot pins to plastic box. I bead blasted the shaft stubs to clean all the rust there so they swing easily. I have enough parts n pieces to build up 2 HVAC boxes out of the 3 that I dismantled. I have a complete box worth of junk parts but not all from the same heater box. One bad heater core,one bad evaporator, one busted housing, one busted motor side cover, one rotten recirc door,but not all from the same heater box. All had at least 1 bad non reusable part. And if I can't refoam at least 1 recirc door, I'm stuck.