rubber flap on firewall 67 dodge polara

hey guys, I have the engine out of my 67 polara and am going to paint the firewall and such. there was a black rubber or plastic oval kind of flap in the middle of the firewall attached with 2 little nubbies which of course tore off during removal. Can anyone tell me first of all what this piece is, and 2nd is there a replacement available from someone? I appreciate any info out there!!
Author: The Mechanic